This is a powerpoint presentation that discusses about the topic or lesson: Thomson's Atomic Model. It also includes the history of Joseph John Thomson, characteristics and concepts of Thomson's Atomic Model.
This is a powerpoint presentation that discusses about the topic or lesson: Dalton's Atomic Model. It also includes the history of John Dalton, characteristics and concepts of Dalton's Atomic Model.
This is a powerpoint presentation that discusses about the topic or lesson: Thomson's Atomic Model. It also includes the history of Joseph John Thomson, characteristics and concepts of Thomson's Atomic Model.
This is a powerpoint presentation that discusses about the topic or lesson: Dalton's Atomic Model. It also includes the history of John Dalton, characteristics and concepts of Dalton's Atomic Model.
Students, digital devices and success - Andreas Schleicher - 27 May 2024..pptxEduSkills OECD
Andreas Schleicher presents at the OECD webinar ‘Digital devices in schools: detrimental distraction or secret to success?’ on 27 May 2024. The presentation was based on findings from PISA 2022 results and the webinar helped launch the PISA in Focus ‘Managing screen time: How to protect and equip students against distraction’ https://www.oecd-ilibrary.org/education/managing-screen-time_7c225af4-en and the OECD Education Policy Perspective ‘Students, digital devices and success’ can be found here - https://oe.cd/il/5yV
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.
How to Split Bills in the Odoo 17 POS ModuleCeline George
Bills have a main role in point of sale procedure. It will help to track sales, handling payments and giving receipts to customers. Bill splitting also has an important role in POS. For example, If some friends come together for dinner and if they want to divide the bill then it is possible by POS bill splitting. This slide will show how to split bills in odoo 17 POS.
This is a presentation by Dada Robert in a Your Skill Boost masterclass organised by the Excellence Foundation for South Sudan (EFSS) on Saturday, the 25th and Sunday, the 26th of May 2024.
He discussed the concept of quality improvement, emphasizing its applicability to various aspects of life, including personal, project, and program improvements. He defined quality as doing the right thing at the right time in the right way to achieve the best possible results and discussed the concept of the "gap" between what we know and what we do, and how this gap represents the areas we need to improve. He explained the scientific approach to quality improvement, which involves systematic performance analysis, testing and learning, and implementing change ideas. He also highlighted the importance of client focus and a team approach to quality improvement.
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
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
2. Learning Objectives
• You should be able to:
– Discuss the development of the atom from its
earliest model to the modern day atom.
– Identify the correct number of subatomic
particles for atoms, ions, and isotopes.
– Calculate the average atomic mass and mass
number of an atom from isotopic data.
3. Atoms & Elements
• An atom is the smallest particle of an element
that retains it identity in a chemical reaction.
• Elements are the simplest form of matter that
has a unique set of properties; an element
cannot be broken down into simpler substances
by chemical means.
5. Ancient Philosophy
• Who: Democritus (460 BC – 370 BC)
• When: 400 BC
• Where: Greece
• What: Democritus believed that matter was made of
small particles he named “atomos”. Democritus
believed that atoms were indivisible and
indestructible, and that different types of atoms had
different sizes and shapes.
• How: Democritus used observation and inference to
explain the existence of everything; examined
broken sea shells to generate his concept of atoms.
6. Atomic Theory
• Who: John Dalton (1766-1844)
• When: 1803
• Where: England
• Why: Building on the ideas of Democritus in ancient
Greece; applied scientific reasoning.
• What: ”Billiard Ball Model” -Described atoms as tiny
invisible particles that could not be created,
destroyed, or divided. Thought each element was
made of its own kind of atom.
• How: Studied gases, pressure and temperature
changes.
7. 4 Hypotheses of Dalton’s Atomic Theory
1. All matter is composed of tiny particles called atoms.
2. Atoms of the same element are identical. The atoms of
any one element are different from those of any other
element.
3. Atoms of different elements can physically mix
together or can chemically combine in simple whole-
number ratios to form compounds.
4. Chemical reactions occur when atoms are separated,
joined, or rearranged. Atoms of one element, however,
are never changed into atoms of another element as a
result of a chemical reaction.
Dalton’s Atomic Theory
9. Foundations of Atomic Theory
Law of Definite Proportions (Proust)
The fact that a chemical compound contains the same elements
in exactly the same proportions by mass regardless of the size
of the sample or source of the compound.
Law of Multiple Proportions (Dalton)
If two or more different compounds are composed of the
same two elements, then the ratio of the masses of the
second element combined with a certain mass of the first
elements is always a ratio of small whole numbers.
Law of Conservation of Mass (Lavoisier)
Mass is neither destroyed nor created during ordinary chemical
reactions.
10. Discovery of Electrons
• Who: J. J. Thomson (1856-1940)
• When: 1897
• Where: England
• What: ”Plum Pudding Model” –Described atoms as
a solid sphere of positively charged material having
negatively charged electrons spread throughout.
Thomson discovered that electrons were smaller
particles of an atom and were negatively charged.
• Why: Thomson knew atoms were neutrally
charged, but couldn’t find the positive particle.
• How: Cathode Ray Experiment
12. Atomic Structure I
• Who: Ernest Rutherford (1871-1937)
• When: 1911 & 1920
• Where: England
• What: “Planetary Model” -Decided that atoms were
mostly empty space, but had a dense central core
(nucleus-1911) consisting of positively charged
protons (1920); electrons orbit the nucleus.
• Why: He knew that atoms had positive and negative
particles, but could not decide how they were
arranged.
• How: Gold Foil Experiment – isolated the protons.
14. Atomic Structure II
• Who: Niels Bohr (1885-1962)
• When: 1913
• Where: England
• What: “Bohr Model” -Proposed that electrons traveled
in fixed paths (energy levels) around the nucleus;
every atom has a defined number of energy levels.
Scientists still use the Bohr model to show the number of electrons in each
orbit around the nucleus.
• Why: Bohr was trying to show why the negative
electrons were not sucked into the nucleus of the atom.
• How: Worked with frequency and wavelength of
radiation; applied math.
16. Modern Concept of the Atom
• Electrons travel around the nucleus in random orbits.
• Scientists cannot predict where they will be at any
given moment.
• Electrons travel so fast, they appear to form a “cloud”
around the nucleus.
• The analogy is that of a “beehive” where the bees
are the electrons moving around the nucleus in a
“cloud” of energy levels.
• Major contributions from many scientists, including
Schrödinger (1926) and Chadwick (1932).
17. Modern Concept of the Atom
• Who: Erwin Schrödinger (1887-1961)
• When: 1926
• Where: Austria
• What: “Electron Cloud Model” -Proposed that
electrons are not confined to fixed energy levels;
rather they occupy volumes of space outside the
nucleus; electron energy is based on its location
(increases away from nucleus)
• How & Why: Used math to explain the probable
location of electrons; the denser the electron cloud,
the more likely the electron will be there.
19. Modern Concept of the Atom
• Who: James Chadwick (1891-1974)
• When: 1932
• Where: England
• What: “Nuclear Model” –Discovered the neutron;
proposed that neutrons are neutral particles located in
the nucleus of an atom and have a mass about that of
a proton.
• Why: Expanded upon Rutherford’s experiments; If
nuclei contained only protons their charge would be
much higher than measurements suggested.
• How: Used a neutron chamber in his experiments.