This document provides an introduction to working as a chemist. It outlines the scientific method and defines key terms like facts, laws, hypotheses, independent and dependent variables. It also lists the SI units used to measure common properties in chemistry like mass, length, temperature and concentration. Students are assessed on their understanding of concepts like accuracy, precision, significant figures and processing quantitative and qualitative data. Related concepts and terminology are defined to aid understanding.
I have attached here with 104 pages of PDF about Laboratory equipments and uses, Common laboratory techniques, Substances available in a laboratory (I. Solid II. Liquids III.Metals) Safety symbols and Lab safety
I have attached here with 104 pages of PDF about Laboratory equipments and uses, Common laboratory techniques, Substances available in a laboratory (I. Solid II. Liquids III.Metals) Safety symbols and Lab safety
This presentation will help you understand the common lab glassware & their uses. For more info please visit : https://www.scienceequip.com.au/glassware/
Handling of chemicals, handling of acids, ethers, calibration of burette, pipette, Heating methods, stirring methods, filtratio techniques, chemical balance and single pan balance
I use this lab sequence over a couple of lessons to get to grips with some basics of different types of reactions, balancing, writing formulas and problem-solving.
This presentation will help you understand the common lab glassware & their uses. For more info please visit : https://www.scienceequip.com.au/glassware/
Handling of chemicals, handling of acids, ethers, calibration of burette, pipette, Heating methods, stirring methods, filtratio techniques, chemical balance and single pan balance
I use this lab sequence over a couple of lessons to get to grips with some basics of different types of reactions, balancing, writing formulas and problem-solving.
How International Is Our School? MA DissertationStephen Taylor
Title: A pilot-test of a visualization and set of evaluation rubrics for factors affecting the promotion of international-mindedness and global engagement (IMaGE) of a school.
In this formative in-class Criterion C task, we connect the content from the last unit with some basics on Forces, using the Red Bull Stratos jump as a basis.
Defining Inquiry for the PreK-12 continuum. Inquiry as a 'theory of everything' of good education, built on a solid foundation of well-taught knowledge, skills and concepts.
MA International Education University of Bath assignment (Education in and International Context).
In this assignment I have tried to propose an original idea for helping schools define and measure the degree to which they demonstrate the values of international education.
This is an assignment for my University of Bath MA in International Education, based on the tensions in transition from MYP to DP. It revolved around the different schools of through about learning and, most importantly, inquiry. It focuses on the different approaches to inquiry characterised by Dewey and Vygotsky, before moving onto a modern look at evidence-based practices.
This is a document used in my EE summer school sessions. After looking at excellent examples of EE's, examiners' reports, the EE guide and subject-specific guidance, students were given this document.
Assessment Assignment: Bath MA International EducationStephen Taylor
This is an assignment I completed for the Assessment unit of the University of Bath's MA in International Education programme.
It is shared here to allow me to embed it onto my professional reflective blog at http://ibiologystephen.wordpress.com
Downloads have been disabled.
In depth overview of scientific method and experimental design. Begins with key goals, vocabulary and the big picture of the basic process. The program breaks down the scientific process using tulips as examples. Covers the entire process including scientific question and hypothesis formation, control and experimental trials, variables and controlling variables. In addition, discusses types of error, reliability and validity. Shows example conclusion as well as gives examples for Validity and Reliability. Designed for initial teaching by elementary and middle school teachers as well as a self paced review for Grades 6-12 and ELL students.
Version 4.3 includes the companion volume on page 2, the Science and the Scientific Process reference guide (pdf). One must download the presentation to view this detailed document.
measurement and scaling is an important tool of research. by following the right and suitable scale will provide an appropriate result of research.this slide show will additionally provide the statistical testing for research measurement and scale.
Review of "Survey Research Methods & Design in Psychology"James Neill
Reviews the 150 hour, third year psychology unit which examined survey research methods, with an emphasis on the second-half of the unit on MLR, ANOVA, power, and effect size.
Universidad Técnica Particular de Loja
Ciclo Académico Abril Agosto 2011
Carrera: Inglés
Docente: Mgs. Orlando Lizaldes E.
Ciclo: Sexto
Bimestre: Segundo
This presentation is for my class to work through as teachers are on a series of PD days. It is based on a very bad One Direction joke cracked in a class about vectors.
I split the presentation for the unit into two, as I added so many slides to help with student questions and misconceptions. This one focuses on mathematical aspects of the unit.
In the first week of High School, my Grade 9 Chemistry class were asked to put on a short show for the BBP and KA students (3-5 year-olds) about water. We used it as a chance to get to know each other and to formatively assess Criterion B: Communication and F: Attitudes in Science.
This was made with Jon Schatzky and Barney Trezona.
As a task in our MYP Areas of Interaction workshop, we worked together to unpack on AOI for students. We chose Approaches to Learning, and then focused on 'Social'. Using the document "Making the PYP Happen' and its trans-disciplinary skills, we then decided to create a rubric for the skill of 'Conflict Resolution'.
Ideas for integrating inquiry and differentiation with AOI'sStephen Taylor
Jon Schatzky and I have been working on some ideas on this MYP workshop. None of the work presented here is definitive, but some of the graphics might be of use. The editable powerpoint is available for download.
Big thanks to Cameron Hall for his great work on visualising the Areas of Interaction.
One World: Scientific Solutions to Global IssuesStephen Taylor
A one or two lesson formative assessment task to introduce students to One World.
Students watch one of two videos which introduce a scientific solution to a problem in a global context. They then prepare a mind-map poster which goes through the stages of the One World criterion.
This is a work in progress, but outlines some of the ways in which home-made concept cartoons are used in my class. It was featured on the SlideShare homepage.
I highly recommend that teachers, especially in Middle School, get a copy of the concept cartoons resources.
Model Attribute Check Company Auto PropertyCeline George
In Odoo, the multi-company feature allows you to manage multiple companies within a single Odoo database instance. Each company can have its own configurations while still sharing common resources such as products, customers, and suppliers.
Biological screening of herbal drugs: Introduction and Need for
Phyto-Pharmacological Screening, New Strategies for evaluating
Natural Products, In vitro evaluation techniques for Antioxidants, Antimicrobial and Anticancer drugs. In vivo evaluation techniques
for Anti-inflammatory, Antiulcer, Anticancer, Wound healing, Antidiabetic, Hepatoprotective, Cardio protective, Diuretics and
Antifertility, Toxicity studies as per OECD guidelines
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
1. Chemistry Lab ManualName:
_____________
Introduction to working as a Chemist.
Use a highlighter as you work through this booklet. ESL students, make vocab lists of the
terminology that is defined or described here.
Assessment Statements
Outline the Scientific Method State SI units of measurement for
Identify independent, dependent & controlled Mass: grams (g)
variables. Length: Metres (m), millimeters (mm)
Demonstrate correct and safe use of laboratory Concentration: molarity (M)
o
equipment. Temperature: Degrees Celsius ( C)
Distinguish between quantitative and qualitative Volume: Litres (L) or millitres (mL)
data Density: grams per cubic centimeter
3
Qualitative is descriptive, not using (g/cm )
numbers, e.g. properties, colour, gas Conductivity: Siemens (S)
production, sound, odor. Acidity or alkalinity (pH)
Quantitative is mathematical, including Energy: Joules (J or kJ)Determine the
Raw data (as recorded ) uncertainty of digital and analog measuring tools
Processed (after calculations) Usually ± 1 of the smallest division
Distinguish between accuracy and precision Calculate the % error of a given or recorded set
Accuracy describes the correctness of a of values
set of measurements ((Measured – True) / True) x 100
Precision describes the repeatability of a State values to appropriate numbers of
set of measurements significant figures
Calculate values to appropriate numbers of
significant figures
Related Concepts:
01.1 Element symbols (Quia quiz: http://www.quia.com/quiz/3246640.html)
01.2 Accuracy, Precision, Error, Uncertainty (Quia quiz: http://www.quia.com/quiz/3507626.html)
01.3 SigDigs and Notation (Quia quiz: http://www.quia.com/quiz/3504378.html)
Command Terms: Be sure you understand what is being asked of you
Analyse Break down to identify key parts. Interpret information to reach conclusions.
Apply Use knowledge & understanding in response to a real situation or given circumstances.
Calculate Obtain a numerical answer, showing relevant stages in the working.
Define Give the precise meaning of a word, phrase, concept or physical quantity.
Describe Give a detailed account or picture of an event, pattern, process or pattern.
Design Produce a plan, simulation or model.
Determine Obtain the only possible answer.
Discuss Offer a considered and balanced review that includes a range of arguments, factors or hypotheses.
Opinions or conclusions should be presented clearly and supported by appropriate evidence.
Distinguish Make clear the differences between two or more concepts or items.
Evaluate Assess the implications and limitations; make judgments about the ideas, works, solutions
or ideas in relation to selected criteria.
Explain Give a detailed account including reasons or causes.
Identify Provide an answers from a number of possibilities. Recognise and state briefly a
distinguishing fact or feature.
Label Add title, labels or brief explanation(s) to a diagram or graph.
List Give a sequence of answers with no explanation.
Outline Give a brief account.
Recall Remember or recognize from prior learning experiences.
State Give a specific name, value or other brief answer without explanation or calculation.
Suggest Propose a solution, hypothesis or other possible answer.
1
2. Use Apply knowledge or rules to put theory into practice.
2
3. AssessmentSubmit for checking once complete. Ask for help when needed.
Criterion F: Attitudes in Science(Highlight the statements that best fit your effort)
Level Level descriptor
0 The student does not reach a standard described by any of the descriptors below.
1–2 The student requires some guidance to work safely and some assistance when using material and equipment.
The student requires some guidance to work responsibly with regards to the living and non-living
environment.
When working as part of a group, the student needs frequent reminders to cooperate with others.
3–4 The student requires little guidance to work safely and little assistance when using material and equipment.
The student works responsibly with regards to the living and non-living environment.
When working as part of a group the student cooperates with others on most occasions.
5–6 The student requires no guidance to work safely and uses material and equipment competently.
The student works responsibly with regards to the living and non-living environment.
When working as part of a group, the student cooperates with others.
Expectations:
Your working area and personal space are kept clean and neat at all times.
You work safely with regard to chemicals, equipment and others.
You are sensible and precise in your use of science equipment and materials.
All equipment is properly cleaned and returned to the proper place.
You show cooperation and respect for others in your group work.
Comments:
Criterion E: Processing Data (Formative) (Highlight the statements that best fit your effort)
Level Level descriptor
0 The student does not reach a standard described by any of the descriptors below.
1–2 The student collects some data and attempts to record it in a suitable format.
The student organizes and presents data using simple numerical or visual forms.
The student attempts to identify a trend, pattern or relationship in the data.
The student attempts to draw a conclusion but this is not consistent with the interpretation of the data.
3–4 The student collects sufficient relevant data and records it in a suitable format.
The student organizes, transforms and presents data in numerical and/or visual forms, with a few errors or
omissions.
The student states a trend, pattern or relationship shown in the data.
The student draws a conclusion consistent with the interpretation of the data.
5–6 The student collects sufficient relevant data and records it in a suitable format.
The student organizes, transforms and presents data in numerical and/or visual forms logically and correctly.
The student describes a trend, pattern or relationship in the data and comments on the reliability of the data.
The student draws a clear conclusion based on the correct interpretation of the data and explains it using scientific reasoning.
Comments:
3
4. The Scientific Method
Science is never about proving something right or wrong. It is about making observations, forming
hypotheses and developing methods to test those hypotheses. If the data support our hypothesis,
we can try to explain why. If not, we develop a new hypothesis and a new method to test that.
Use the correct language!
A FACT is something that is observable and true.
It is a fact that the Sun shines. It is a fact that reacting HCl and Mg produces a gas.
A LAW is something that always happens in defined conditions, following “if.. then…” rules.
The Law of Conservation of Mass states that atoms (matter) can neither be created nor destroyed. If a
reaction occurs, then all the atoms involved as reactants must be accounted for in the products.
The Law of Diffusion states that molecules in fluids (liquid, solution or gas) will diffuse from areas of
high concentration to areas of low concentration. If the concentration gradient is high, the rate of
diffusion will be faster.
A HYPOTHESIS is a scientific prediction that is testable and can be explained with a reason.
A NULL Hypothesis is the standard against which we compare the outcome.
“There is no significant difference/ effect of... on…”
The ALTERNATE Hypothesis is your prediction:
It makes clear the independent and dependent variables
Independent Variable (IV): The variable that is being changed
- Usually requires at least five increments (different values)
- Usually plotted as the x-axis on a graph
Dependent Variable (DV): The variable that is being measure in response to the IV
- Usually plotted as the y-axis on a graph
It predicts how incremental changes in the independent variable could affect the magnitude of the
dependent variable.
It can be testable under Controlled Conditions
Controlled Variables: all the factors that might impact the outcome of the investigation must be
kept at the same value to ensure the results are reliable.
HYPOTHESIS TESTING
Good scientists design reliable experiments to test the validity of the hypothesis
RELIABILITY:
Is the method easily repeated? Is it free of random and systematic error?
Are the results reliable? This is indicated by the variability of the data.
VALIDITY:
To what extent does the method allow the RQ to be addressed?
To what extent is do the results support the hypothesis?
A THEORY is the highest level of certainty in science. It is supported by lots of empirical evidence.
It has been tested over and over again and can be explained scientifically. It has not been
disproven… yet.
Atomic theory states that all matter is composed of atoms, made up of a nucleus containing protons
and neutrons, outside which is a cloud of electrons.
Kinetic theory of gases state that particles (atoms and molecules) in gases are moving randomly,
colliding with each other. They move more rapidly at high temperature.
Cell theory states that all living things are made of cells; cells are the smallest units of life; cells come
only from other cells.
4
5. What is/areDATA?
“Not everything that can be counted counts. Not everything that counts can be
counted.” Albert Einstein.
QUANTITATIVE DATA (EMPIRICAL DATA)
Can be measured and compared using numbers
Can be continuous or non-continuous.
Continuous: on a scale, such as time, temperature, concentration
Non-continuous: not scaled, such as categories, groups.
Includes the values of the increments of the IV
Includes raw and processed data of the DV
Raw data includes all numbers recorded during the experiment.
Processing shows how transformations work with the data: calculations
Processed data are the the final results, after calculations
Presented data are the tables and graphs that are produced
QUALITATIVE DATA (OBSERVATIONAL DATA)
Descriptive, not numerical
Provides important insights that might help explanations
Both types of data are essential in lab reports.
……….o0O0o………..
There’s no such word as ‘amount’!
What do you really mean when you say “amount”?
Matter is anything that has mass and volume(takes up space):
We measure mass in kilograms (kg), or grams (g).
We measure volume in litres (L) or millilitres (mL) (sometimes cm3).
We also describe other quantities:
Time in seconds (s)
Length or distance in metres (m)
Energy in joules (J) or kilojoules (kJ)
Heat/temperature in degrees Celcius (oC) (the SI* unit is Kelvin, K)
Quantity of a substance in moles (mol)
Concentration of a solution in moles per litre (M)
Acidity or alkalinity in pH (0 is a strong acid, 7 is neutral, 14 a strong base)
Electrical conductivity of a solutionin Siemens (S)
*Standard International (SI)units are based on the metric system – numbers that divide easily
into tens and hundreds. Most countries in the world use these units and it makes calculations
more straightforward.
In this activity, we’ll learn how to measure some of these physical quantities using the appropriate
tools in the lab. Complete this lab manual as you go along – you will use it as a tool throughout the
course.
5
6. Safety First
We must be safe in the lab at all times. Check that you can find these:
Goggles What should you do if there is an accident in the lab?
Fire blanket
Fire extinguisher
Phone Do not try to clean up broken glass – MrT will do it.
Safe Bunsen ‘driving license’
How do you turn on the Bunsen?
……………………………………………………………………………………………………
……………………………………………………………………………………………………
What is the ‘safety flame’?
…………………………………………………………………………………………………
…………………………………………………………………………………………………
What is the ‘roaring flame’ and which part is the hottest?
…………………………………………………………………………………………………
…………………………………………………………………………………………………
NEVER point a hot container towards yourself or others.
ALWAYS be careful in the Chemistry Lab!
Visual guide to Chemistry Lab equipment
As you work through the tasks, draw some simple diagrams of the lab equipment to help you
remember the names.
Beaker Conical flask Test tube
Tripod & Gauze mat Test tube tongs Wash bottle
Pasteur (dropping) pipette Filter funnel Spatula
6
7. Units and Uncertainty (Quia quiz: http://www.quia.com/quiz/3507626.html)
All measurements have uncertainties – a range of values in which the true measurement could lie.
More precise measuring tools have a smaller degree of uncertainty.
Significant Digits (or Significant Figures) Tutorial:http://is.gd/sigfigs
We use significant digits to communicate how precise a measurement is – how certain we are in
our measurement. In the example above, there are 4 significant digits.
Significant digits are:
All non-zero digits (and all the zeroes in-between non-zeroes!)
Any digits after a decimal point
But they are NOT:
Leading zeroes, e.g. 0.000345 has only 3 sigdigs: 345
Trailing zeroes with no decimal, e.g. 10,000 has only 1 sigdig (we can’t tell if it is
exactly 10,000 or a number that is close and has been rounded).
How many significant digits in these numbers? Write these numbers to 3 sigdigs:
123.45 _________ sig digits
12420 = _______________
123000 _________ sig digits
1.008 _________ sig digits 0.03209 = _______________
01.67 _________ sig digits
4050.0 = _______________
1000 _________ sig digits
1000.0 _________ sig digits 0.0101010 = ______________
Calculating Significant Digits
We can only report values to the minimum degree of certainty, so:
When adding or subtracting, use the number of decimal places of the weakest value.
When multiplying or dividing, use the number of sigdigs of the weakest value.
1. 2.01 - 1.0 = 5. 3.44–4.0 =
2. 123 + 456.789 = 6. 1.23 + 45.6 =
3. 1.2 x 3.45 = 7. 0.66 x 1.34 =
4. 34.678 /3.33 = 8. 1.34 / 0.66 =
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8. Accuracy, Precision & Errors (Quia quiz: http://www.quia.com/quiz/3507626.html)
There is always an element of error in our measurements.
The accuracy of a measurement is how close it lies to the true value (“correct
answer”). The precision of a measurement is how repeatable that measurement is.
Identify which of the dartboards shows (Circle):
1. High precision and high accuracy? Top - Middle - Bottom
2. Low precision and low accuracy? Top - Middle - Bottom
3. High precision but low accuracy? Top - Middle - Bottom
Systematic error is an error that is the same for all measurements and can be
adjusted. For example, a digital balance that is poorly calibrated might measure
0.5g too much each time.
Random error is not consistent between measurements and cannot be adjusted.
For example, errors introduced by using different recording tools or people.
Identify which of the dartboards shows:
4. Random error: Top - Middle – Bottom 5. Systematic error: Top - Middle - Bottom
Dartboard diagrams from http://preparatorychemistry.com/Bishop_Book_1_eBook.pdf
Scientific Notation (Quia quiz: http://www.quia.com/quiz/3504378.html)
Often we produce measurements or readings with a large number of zeroes.
We use scientific notation to present these numbers in a clear, standard format.
Simple rules:
There is alwaysone digit before the decimal
It always ends x 10x(“times ten to the power of x”)
Significant digits are important. The examples below have 3sigdigs (1.23)
The value of x tells us how many places the decimal has been moved.
If you are making a large number small, x is positive.
If you are making a small number (less than zero) larger, X is negative.
e.g. 1230000000000 can be written as 1.23 x 1012
The decimal has moved 12 places to the left.
e.g. 0.000000000123 can be written as 1.23 x 10-10
The decimal has moved 10 places to the right.
Expand the following notations:
1.0 X 103= ______________________ 4.56 X 105= _____________________________
1.0 X 10-6= ______________________ 7.01 X 10-4= _____________________________
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9. Statethe following in scientific notation to 3 significant digits:
• 12340000 = _____________________________
• 00012340 = _____________________________
• 10101010 = _____________________________
Compare the following measurements:
3.04 x 104 kJ 3.040 x 104 kJ 3.0400 x 104 kJ
What is a Solution?
A solution is a homogenous* mixture of a substance in a liquid.
The solvent is the liquid, e.g. water or alcohol, which dissolves the…
Solute, which is the solid, e.g. salt or sugar.
Label the solventand the solute in the beaker to the right. ----------->
*mixtures can be:
Homogenous = evenly distributed, like solutions
Heterogeneous = unevenly distributed, like soup, oceans,
mixtures of solids.
Beaker from: http://www.wpclipart.com/science/beaker/beaker.png.html
Concentration of a Solution
A more concentrated solution contains more molecules per unit volume.
We measure the concentration of a solution by the number of moles of solute it contains per litre.
This is called molarity, and uses the unit ‘M’.
A 1M solution contains 1mole of solute per litre.
One ‘mole’ of a substance is 6.02 x 1023 units (atoms or molecules).
So a 1M solution of sugar has 6.02 x 1023 molecules of sugar per litre.
Expand the notation above.
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10. Measuring Volume
We use graduated cylinders to measure volumes of a liquid. We do not use beakers or conical
flasks – the marks on those are estimates only.
Label the meniscus on the diagram to the right.
This is where we measure fluids.
Put the cylinder on the table and move your eyes to read it.
Observe these different-sized measuring cylinders. Complete the table.
Size Markings every… Recorded volume (ml) Uncertainty (± )
10mL
50mL
100mL
Identify which cylinder has:
1. The most precise gradations (markings): _______ mL
2. The biggest uncertainty: _______ mL
Add up the total volume of water in the four cylinders. Present your working and give the answer
to the most appropriate significant digits. Explain your answer.
…………………………………………………………………………………………………………………………………………..
…………………………………………………………………………………………………………………………………………..
…………………………………………………………………………………………………………………………………………..
…………………………………………………………………………………………………………………………………………..
Measuring Mass
We use digital balances to measure the mass of a substance.
Check the range of the balance – do not press on it or add a
mass that is heavier than the maximum. You will break it.
Use a measuring tray or paper on top of the stage. “Tare” (“zero”) it if you need to.
Never stack balances, push hard on the tray or drop them.
Never get the balance wet or dirty.
Choose one known mass and measure it using three different balances. Complete the table.
Balance Range (g) Recorded mass (g) Uncertainty (± ) What is this balance good for?
A
B
C
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11. Measuring Temperature
Compare the glass thermometer with the temperature probe on the data logger.
Remember: Thermometers and dataloggers are NOT for stirring!
Measure the temperature of the solution/ liquid – NOT the container
Don’t touch the thermometer or probe against the glass
Wait for the temperature to stabilize before taking the reading
Which would you choose to get
Glass thermometer oC (± ) quick readings of a reaction that
changes temperature?
Temperature probe oC (± )
Measuring pH
We use pH probes on the datalogger to measure the acidity or
alkalinity of a solution. Strong acids have low pH, neutral pH is 7 and
strong bases have high pH.
Measuring Conductivity
In some solutions, ions form. These are positive ions (cations +) or
negative ions (anions -). When these ions move, they carry electrical
charge, which can be detected with the conductivity probe. A high
concentration of ions will give a high conductivity.
pH scale from:http://www.ec.gc.ca/acidrain/kids.html
Take care of the probes:
Make sure the electrolyte bottle is secure when not being used.
Rinse gently with distilled water between every reading.
Do not stir or shake the probe.
Taking readings:
Submerge the probe and wait for the reading to stabilize
Record the pH to an appropriate level of precision
Record the pHand conductivityof these three solutions:
Solution A B C
pH (± )
conductivity
μS (± )
This symbol means ‘micro’ or one-thousandth.
1 μS = 0.001 S (Siemens is the unit of conductivity)
Probes must be calibrated regularly to make sure they are accurate (to avoid systematic error).
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12. Matter, Elements & The Periodic Table Draw a helium atom:
Matter is anything that has mass and volume (takes
up space).
All matter is made of atoms, which contain:
Protons & neutrons in a central ‘nucleus’
A cloud of electrons
The number of protons is the atomic number and defines the element.
An element is a substance that is made up only of atoms that contain the same number of
electrons.
The periodic table arranges elements based on atomic number, as well as into groups with similar
chemical and atomic properties.
It is very helpful to know the names of the most common elements, so that you can recognize them from
formulas and use them more quickly in your work. We will remember these elements, and complete some
quizzes to help us do so. Try this quiz, which changes each time: http://www.quia.com/quiz/3246640.html
Some rules:
The first letter of the element symbol is always CAPITALISED, but any other letters must be lower-case
Only capitalize the first letter of the name when it starts a sentence. Do not use capitals otherwise. e.g. the first
element is hydrogen
Symbol Name Symbol Name Symbol Name
H hydrogen Cl Sn
He helium Ar I
Li lithium K Xe
Be beryllium Ca Cs
B boron Cr Ba
C carbon Mn Pt
N nitrogen Fe Au
O oxygen Co Hg
F fluorine Ni Pb
Ne neon Cu At
Na sodium Zn Rn radon
Mg magnesium Br Fr francium
Al aluminium Kr Ra radium
Si silicon Rb U uranium
P phosphorous Sr Pu plutonium
S sulphur Ag
Compounds are formed when two or more elements are combined chemically.
Mixtures are made up of two or more substances that are not combined chemically. Each
substance keeps its own properties. Mixtures can be separated:
Filtration separates differently-sized solid particles, or solids from liquids/ solutions.
Evaporation separates a solute from a solvent in a solution.
Distillation (evaporation and condensation) separates liquids based on their boiling point.
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