The document provides information about matter and its various states. It defines matter as anything that occupies space and has mass. It then discusses the physical and chemical classification of matter and describes the three common states of matter - solids, liquids, and gases. The summary discusses their key properties and how changes in temperature and pressure can cause changes between these different states through processes like melting, boiling, evaporation, and sublimation. It also explains some phenomena related to these state changes like the cooling effect of evaporation.
It is my friend's PPT for School Science Seminar made by Me. He stand at 1st position in the Seminar. Its the 1st chapter of class 9th Science of CBSE. Just View and You will definitely like it.
It is my friend's PPT for School Science Seminar made by Me. He stand at 1st position in the Seminar. Its the 1st chapter of class 9th Science of CBSE. Just View and You will definitely like it.
Class 10 l Science l Chemistry l Lesson 1: Chemical equations and reactionsMoulyaT
This is a PPT of chemistry science class 10 "chemical equations and reactions". This is also a very helpful material for notes. Please find it helpful and don't forget to like this PPT for my efforts. Thank you :-)
Chapter - 2, Is matter around us pure?, Science, Class 9Shivam Parmar
I have expertise in making educational and other PPTs. Email me for more PPTs at a very reasonable price that perfectly fits in your budget.
Email: parmarshivam105@gmail.com
Chapter - 2, Is matter around us pure?, Science, Class 9
PURE SUBSTANCES
WHAT IS A MIXTURE?
HOMOGENEOUS MIXTURE
HETEROGENEOUS MIXTURE
DIFFERENCE BETWEEN MIXTURES AND COMPOUNDS
SOLUTION
PROPERTIES OF SOLUTION
DIFFERENT TYPES OF SOLUTIONS
CONCENTRATION
SUSPENSION
COLLOIDAL SOLUTION
PROPERTIES OF COLLOIDS
TYNDALL EFFECT
COMPONENTS OF COLLOID
SEPARATING THE COMPONENTS OF A MIXTURE
PHYSICAL CHANGE
CHEMICAL CHANGE
Every topic of this chapter is well written concisely and visuals will help you in understanding and imagining the practicality of all the topics.
By Shivam Parmar (Entrepreneur)
This chapter is for class 9 based on CBSE curriculum in which physical nature of matter, its characteristics are discussed along with states of matter, their inconversion, scales of temperature and difference between boiling and evaporation and factors affecting evaporation with inforgraphics and key points.
Class 7th science chapter 8. Winds, Storms and CyclonesSwayam Khobragade
This ppt file is converted into pdf so if u want to use it you may download it and convert it into ppt so u can use it for expaining the concepts of this chapter...... This ppt contains only the information given in the textbook.. This ppt also have the keywords,exercises and other basic knowledge....
Best PowerPoint presentation on NCERT class 9 Atoms and Molecules as per CBSE syllabus it covers full chapter with all information.
By Raxit Gupta
9C
KENDRIYA VIDYALAYA BALLYGUNGE
SOUND
MUSICAL INSTRUMENT
PROPAGATION OF SOUND
PRODUCTION OF SOUND MUSICAL INSTRUMENTS
SPEED OF A SOUND
WOODWINDS INSTRUMENTS
String INSTRUMENTS
Percussion INSTRUMENTS
Brass INSTRUMENTS
SOUND PRODUCED BY HUMANS
SPEED OF LIGHT V/S SOUND
SOUND PRODUCED BY ANIMAL
VIBRATION & OSCILLATION
LOUDNESS AND PITCH OF SOUND
HUMAN EARS
PERSISTENCE OF HEARING
Echo & REVERBERATION
AUDIBLE AND INAUDIBLE SOUND
NOISE AND MUSICAL SOUND
Noise pollution
HEARING IMPAIRMENT
SIGN LANGUAGE
Reflection of sound
Uses of multiple reflection of sound
SONAR
Class 10 l Science l Chemistry l Lesson 1: Chemical equations and reactionsMoulyaT
This is a PPT of chemistry science class 10 "chemical equations and reactions". This is also a very helpful material for notes. Please find it helpful and don't forget to like this PPT for my efforts. Thank you :-)
Chapter - 2, Is matter around us pure?, Science, Class 9Shivam Parmar
I have expertise in making educational and other PPTs. Email me for more PPTs at a very reasonable price that perfectly fits in your budget.
Email: parmarshivam105@gmail.com
Chapter - 2, Is matter around us pure?, Science, Class 9
PURE SUBSTANCES
WHAT IS A MIXTURE?
HOMOGENEOUS MIXTURE
HETEROGENEOUS MIXTURE
DIFFERENCE BETWEEN MIXTURES AND COMPOUNDS
SOLUTION
PROPERTIES OF SOLUTION
DIFFERENT TYPES OF SOLUTIONS
CONCENTRATION
SUSPENSION
COLLOIDAL SOLUTION
PROPERTIES OF COLLOIDS
TYNDALL EFFECT
COMPONENTS OF COLLOID
SEPARATING THE COMPONENTS OF A MIXTURE
PHYSICAL CHANGE
CHEMICAL CHANGE
Every topic of this chapter is well written concisely and visuals will help you in understanding and imagining the practicality of all the topics.
By Shivam Parmar (Entrepreneur)
This chapter is for class 9 based on CBSE curriculum in which physical nature of matter, its characteristics are discussed along with states of matter, their inconversion, scales of temperature and difference between boiling and evaporation and factors affecting evaporation with inforgraphics and key points.
Class 7th science chapter 8. Winds, Storms and CyclonesSwayam Khobragade
This ppt file is converted into pdf so if u want to use it you may download it and convert it into ppt so u can use it for expaining the concepts of this chapter...... This ppt contains only the information given in the textbook.. This ppt also have the keywords,exercises and other basic knowledge....
Best PowerPoint presentation on NCERT class 9 Atoms and Molecules as per CBSE syllabus it covers full chapter with all information.
By Raxit Gupta
9C
KENDRIYA VIDYALAYA BALLYGUNGE
SOUND
MUSICAL INSTRUMENT
PROPAGATION OF SOUND
PRODUCTION OF SOUND MUSICAL INSTRUMENTS
SPEED OF A SOUND
WOODWINDS INSTRUMENTS
String INSTRUMENTS
Percussion INSTRUMENTS
Brass INSTRUMENTS
SOUND PRODUCED BY HUMANS
SPEED OF LIGHT V/S SOUND
SOUND PRODUCED BY ANIMAL
VIBRATION & OSCILLATION
LOUDNESS AND PITCH OF SOUND
HUMAN EARS
PERSISTENCE OF HEARING
Echo & REVERBERATION
AUDIBLE AND INAUDIBLE SOUND
NOISE AND MUSICAL SOUND
Noise pollution
HEARING IMPAIRMENT
SIGN LANGUAGE
Reflection of sound
Uses of multiple reflection of sound
SONAR
CHANGEOF STATE
STATES OF MATTER
There are three states, or phases, of matter.
They are:
Solid
Liquid
Gas
When a substance changes from one state, or phase, of matter to another we say that it has undergone a change of state.
MELTING
The change of state from solid to liquid state is called melting.
The temperature at which the solid states of the substance changes into the liquid states of the substance is called its melting point.
The temperature remains constant until the entire amount solid is converted into liquid state
VAPORISATION
The change of state from liquid to vapour is called vaporisation.
The liquid and vapour states of the substance coexist in thermal equilibrium during the change of state from liquid to vapour.
The temperature at which the liquid states of the substance change to its vapour state is called its boiling point.
CONDENSATION
The process of changing gas (or vapour) to a liquid by cooling is called condensation
Condensation is the reverse of boiling (or vaporisation).
FREEZING
The process f changing a liquid into a solid by cooling is called freezing
Freezing is reverse of melting
Freezing means solidification.
SUBLIMATION AND DESPOSITION
The process of changing of solid directly into vapour (or gas) is called sublimation.
The process of changing of vapour (or gas) directly into solid is called sublimation and desposition.
EFFECT OF PRESSURE ON MELTING POINT
Under normal atmospheric pressure, ice melts at 0 °C. However, this can change if the air pressure changes.
When the two ice cubes are pressed together, the melting point is lowered.
The ice melts since its temperature (0 °C) is above the new melting point.
When the ice cubes are released, the ice freezes again at 0 °C joining the two ice cubes together.
Inside the Atom, Quarks, Leptons, Force Carrier Particles Physical Science Le...www.sciencepowerpoint.com
This PowerPoint is one small part of the Atoms and Periodic Table of the Elements unit from www.sciencepowerpoint.com. This unit consists of a five part 2000+ slide PowerPoint roadmap, 12 page bundled homework package, modified homework, detailed answer keys, 15 pages of unit notes for students who may require assistance, follow along worksheets, and many review games. The homework and lesson notes chronologically follow the PowerPoint slideshow. The answer keys and unit notes are great for support professionals. The activities and discussion questions in the slideshow are meaningful. The PowerPoint includes built-in instructions, visuals, and review questions. Also included are critical class notes (color coded red), project ideas, video links, and review games. This unit also includes four PowerPoint review games (110+ slides each with Answers), 38+ video links, lab handouts, activity sheets, rubrics, materials list, templates, guides, and much more. Also included is a 190 slide first day of school PowerPoint presentation.
Areas of Focus: -Atoms (Atomic Force Microscopes), Rutherford's Gold Foil Experiment, Cathode Tube, Atoms, Fundamental Particles, The Nucleus, Isotopes, AMU, Size of Atoms and Particles, Quarks, Recipe of the Universe, Atomic Theory, Atomic Symbols, #'s, Valence Electrons, Octet Rule, SPONCH Atoms, Molecules, Hydrocarbons (Structure), Alcohols (Structure), Proteins (Structure), Periodic Table of the Elements, Organization of Periodic Table, Transition Metals, Electron Negativity, Non-Metals, Metals, Metalloids, Atomic Bonds, Ionic Bonds, Covalent Bonds, Metallic Bonds, Ionization, and much more.
This unit aligns with the Next Generation Science Standards and with Common Core Standards for ELA and Literacy for Science and Technical Subjects. See preview for more information
If you have any questions please feel free to contact me. Thanks again and best wishes. Sincerely, Ryan Murphy M.Ed www.sciencepowerpoint@gmail.com
Teaching Duration = 4+ Weeks
Chemistry is that branch of science dealing with the study of composition, structure, and properties of matter. It deals with the study of the changes which different forms of matter undergo under different conditions. Chemistry also had branches that look at the laws governing these changes.
The chapters in Organic Chemistry are important for NEET-UG. It carries high weightage in the exam.
lass 11
Chemistry Project on Green Chemistry – Biodiesel and Biopetrol.
Chemistry Project on Calculating the pH Balance and Change.
Chemistry Project on Quantitative Estimation.
Chemistry Project on Rusting of Iron.
Chemistry Project on Characterization and Purification of Organic Substances.
lass 11
Chemistry Project on Green Chemistry – Biodiesel and Biopetrol.
Chemistry Project on Calculating the pH Balance and Change.
Chemistry Project on Quantitative Estimation.
Chemistry Project on Rusting of Iron.
Chemistry Project on Characterization and Purification of Organic Substances.
lass 11
Chemistry Project on Green Chemistry – Biodiesel and Biopetrol.
Chemistry Project on Calculating the pH Balance and Change.
Chemistry Project on Quantitative Estimation.
Chemistry Project on Rusting of Iron.
Chemistry Project on Characterization and Purification of Organic Substances.
lass 11
Chemistry Project on Green Chemistry – Biodiesel and Biopetrol.
Chemistry Project on Calculating the pH Balance and Change.
Chemistry Project on Quantitative Estimation.
Chemistry Project on Rusting of Iron.
Chemistry Project on Characterization and Purification of Organic Substances.
Matter in our surroundings-9TH- NCERT CBSEAmazingTechno
Matter in our surroundings-9TH- NCERT CBSE! I Made It In Class 9TH! I Think This would Help You all! Videos Were There but there was not any source so I removed them! But They Can Be downloaded From Youtube!
Class 9 Chapter 1 Matter in our surrounding ncert cbse board ppt
for school made on canvajjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjsssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
Comparing Evolved Extractive Text Summary Scores of Bidirectional Encoder Rep...University of Maribor
Slides from:
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Track: Artificial Intelligence
https://www.etran.rs/2024/en/home-english/
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
What is greenhouse gasses and how many gasses are there to affect the Earth.moosaasad1975
What are greenhouse gasses how they affect the earth and its environment what is the future of the environment and earth how the weather and the climate effects.
Richard's entangled aventures in wonderlandRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
4. Introduction
Anything which occupies space and has mass is called
matter. If we look around us, we can see a large no
of things of different shapes, sizes and textures.
Many of these things are used by us in our everyday
life. For Example, we eat food, drink water, breathe
in air and wear clothes. We use table and chair for
studying and bed for sleeping. We also see other
human beings, various plants and trees around us.
The things like food, water, air, clothes, table, chair,
human beings, animals, plants, and trees etc., are all
examples of matter
5. Matter In Our Surroundings
Everything in this universe is made up of material
which scientists have named “matter”. The air we
breathe, the food we eat, stones, clouds, stars, plants
and animals, even a small drop of water or a particle
of sand– each thing is matter.
Early Indian philosophers classified matter in the
form of five basic elements –air, earth, fire, sky and
water.
Modern day scientists have evolved two types of
classification of matter based on their physical
properties and chemical nature.
6. Classification of matter
Nowadays scientists have classified matter in the
following two types:-
The physical classification based on physical
properties of matter.
The chemical classification chemical composition of
matter.
7. Matter can be Classified
On the basis of the physical state matter is classified
as solids, liquids and gases.
On the basis of chemical composition matter is
classified as pure substances and mixtures.
• Pure substances may be elements or compounds.
• Mixtures may be homogeneous mixtures or
heterogeneous mixtures.
8. Physical Nature Of Matter
Matter is made up of particles.
The particles of matter are very tiny.
The particles of matter have space between them.
The particles of matter are continuously moving.
The particles of matter attract each other.
9. 1. Matter is made up particles :-
Activity :- Take some water in a beaker and note its
level. Dissolve some salt or sugar in it with the help
of a glass rod. The salt dissolves in the water but the
level of water does not change. This is because the
particles of water get into the space between the
particles of water. This shows that matter is made up
of particles.
10. 2.The particles of matter are very
tiny
Activity :- Dissolve 2 – 3 crystals of potassium
permanganate in 100ml of water in a beaker. Take
10ml of this solution and dissolve in 100ml of water.
Take 10ml of this solution and dissolve in 100ml of
water. Repeat this process 5 – 6 times. This shows
that a few crystals of potassium permanganate can
color a large volume of water because there are
millions of tiny particles in each crystal.
11. 3. The particles of matter have
space between them
Activity :- Take some water in a beaker and note its
level. Dissolve some salt or sugar in it with the help
of a glass rod. The salt dissolves in the water but the
level of water does not change. This is because the
particles of salt get into the space between the
particles of water.
12. 4. Particles of matter are
continuously moving
Activity :- Take some water in a beaker and put a drop
of blue or red ink slowly along the sides of the
beaker. Leave it undisturbed for a few hours. The ink
spreads evenly throughout the water due to the
movement of the particles of water and ink.
The intermixing of two or more different types of
matter on their own is called diffusion.
13. 5. Particles of matter attract each
other :-
Activity :- Take an iron nail, a piece of chalk and a
rubber band. Try breaking them by hammering,
cutting or stretching. It is more easier to break the
chalk, less easier to break the rubber band and
difficult to break the iron nail. This is because the
particles in the iron nail are held together with
greater force than in the rubber band or chalk.
15. A. Properties of solids :-
Solids have definite shapes and fixed volume.
The space between the particle is minimum.
The force of attraction between the particles is
maximum.
The movement of the particles is minimum.
They are least compressible.
Their rate of diffusion is least.
16. B. Properties Of Liquid
Liquids have no definite shape but have fixed
volume. Liquids take the shape of the container.
The space between the particles is intermediate.
The force of attraction between the particles is
intermediate.
The movement of the particles is intermediate.
They are less compressible.
Their rate of diffusion is more than solids.
17. C. Properties Of Gases
Gases have no definite shape or fixed volume. Gases
occupy the whole space of the container.
The space between the particles is maximum.
The force of attraction between the particles is
minimum.
The movement of the particles is maximum.
They are most compressible.
Their rate of diffusion is more than solids and
liquids.
18.
19. Change Of State Of Matter
When a solid is heated it changes into liquid. When a
liquid is heated it changes into gas.
When a gas is cooled it changes to liquid. When a
liquid is cooled it changes into solid.
E.g.:- If ice is heated it changes into water. If water is
heated it changes into steam. If steam is cooled it
changes into water. If water is cooled it changes into
ice.
20.
21. A. Melting Or Fusion
When a solid is heated, the particles begin to vibrate with
greater speed and begin to move more freely. Then at a
particular temperature the solid melts and changes into
liquid. The process of melting is also known as fusion.
The temperature at which a solid melts is called its melting
point. The melting point of ice is 00C or 273 K.
Latent Heat Of Fusion:-The amount of heat energy required to
change 1kg of a solid into liquid at atmospheric pressure at its
melting point is called the latent heat of fusion.
22. B. Boiling
When a liquid is heated, its particles begin to move even faster. Then at a
particular temperature the liquid begins to boil and changes into gas
(vapour).
Boiling is a bulk phenomenon. When a liquid boils the bulk of the liquid
changes into vapour.
The temperature at which a liquid starts boiling is called its boiling point.
The boiling point of water is 1000C or 373K ( 273 + 100).
Latent heat of vaporization :-
The amount of heat energy required to change 1kg of a liquid into gas at
atmospheric pressure at its boiling point is called the latent heat of
vaporization.
23.
24. C. Sublimation
The change of state directly from solid to gas or from
gas to solid is called sublimation.
E.g. :- If solid camphor or ammonium chloride is
heated, it changes into vapour. If the vapours are
cooled it changes into solid.
25. D. Effect of pressure on gases
When pressure is applied on gas the particles come
closer and the gas changes into liquid.
We can liquefy gases by applying pressure and
reducing the temperature.
Compressed solid carbon dioxide is called dry ice. If
the pressure is reduced it changes directly to gas
without coming into liquid state. So solid carbon
dioxide is known as dry ice.
26.
27. Evaporation
The change of a liquid into vapour at any
temperature below its boiling point is called
evaporation.
Evaporation is a surface phenomenon. Particles
from the surface gain enough energy to overcome
the forces of attraction and changes to vapour state.
28. Factors affecting evaporation
The rate of evaporation depends upon surface area,
temperature,
humidity and wind speed.
Increase in the surface area increases the rate of
evaporation.
Increase in temperature increases the rate of
evaporation.
Increase in humidity decreases the rate of
evaporation.
Increase in wind speed increases the rate of
evaporation.
29. Cooling Effect Of Evaporation
When a liquid evaporates, the particles of the liquid absorb
heat from the surroundings and evaporates. So the
surroundings become cold.
E.g. :- People sprinkle water on the roof or open ground
because during evaporation water absorbs heat makes the
hot surface cool.
During summer we sweat more because during
evaporation the sweat absorbs heat from our body making
the body cool.
Wearing cotton clothes in summer keeps us cool because
cotton absorbs sweat and when the sweat evaporates it
absorbs heat from our body making the body cool.