Atomic Structure and the Periodic TablePaul Schumann
Sharon Williams, Water Valley High School
Presented at CAST 2008, ACT2 Strand, 11/6/09
Objectives
Identify important developments in the history of atomic theory.
Summarize Dalton’s atomic theory.
Describe the size of an atom.
Distinguish among protons, electrons, and neutrons in terms of relative mass and change.
Describe the structure of an atom, including the location of the protons, electrons, and neutrons with respect to the nucleus.
Explain how the atomic number identifies an element.
Use the atomic number and mass number of an element to find the number of protons, electrons, and neutrons.
Explain how isotopes differ and why the atomic masses of elements are not whole numbers.
Calculate the average atomic mass of an element from isotope data.
Atomic Structure and the Periodic TablePaul Schumann
Sharon Williams, Water Valley High School
Presented at CAST 2008, ACT2 Strand, 11/6/09
Objectives
Identify important developments in the history of atomic theory.
Summarize Dalton’s atomic theory.
Describe the size of an atom.
Distinguish among protons, electrons, and neutrons in terms of relative mass and change.
Describe the structure of an atom, including the location of the protons, electrons, and neutrons with respect to the nucleus.
Explain how the atomic number identifies an element.
Use the atomic number and mass number of an element to find the number of protons, electrons, and neutrons.
Explain how isotopes differ and why the atomic masses of elements are not whole numbers.
Calculate the average atomic mass of an element from isotope data.
this ppt is all about basic working of most basic unit atom. and could enrich your knowledge about atom. and follow me at my instagram
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Physical Models For Time Dose & FractionationIsha Jaiswal
Physical Models For Time Dose & Fractionation
Strandqvist Plot
Cohen’s Formula
Fowler Concepts
NSD Model
TDF model
Target Theory
L Q model
BED calculation of different fractionation regimen
Introduction
Time dose & fractionation
Therapeutic index
Four R’s Of Radiobiology
Radiation response
Survival Curves Of Early & Late Responding Cells
Various fractionation schedules
Clinical trials of altered fractionation
General management
Management of low grade gliomas: overview
Pilocytic astrocytoma
non pilocytic/diffuse infiltrating gliomas
Management of high grade gliomas: overview
Anaplastic gliomas
Glioblastoma multiformae
EBCTCG METAANALYSIS
INDICATION OF POST OP RADIOTHERAPY
Immobilization devices
Conventional planning
Alignment of the Tangential Beam with the Chest Wall Contour
Doses To Heart & Lung By Tangential Fields
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
Ethnobotany and Ethnopharmacology:
Ethnobotany in herbal drug evaluation,
Impact of Ethnobotany in traditional medicine,
New development in herbals,
Bio-prospecting tools for drug discovery,
Role of Ethnopharmacology in drug evaluation,
Reverse Pharmacology.
The Art Pastor's Guide to Sabbath | Steve ThomasonSteve Thomason
What is the purpose of the Sabbath Law in the Torah. It is interesting to compare how the context of the law shifts from Exodus to Deuteronomy. Who gets to rest, and why?
How to Create Map Views in the Odoo 17 ERPCeline George
The map views are useful for providing a geographical representation of data. They allow users to visualize and analyze the data in a more intuitive manner.
The Indian economy is classified into different sectors to simplify the analysis and understanding of economic activities. For Class 10, it's essential to grasp the sectors of the Indian economy, understand their characteristics, and recognize their importance. This guide will provide detailed notes on the Sectors of the Indian Economy Class 10, using specific long-tail keywords to enhance comprehension.
For more information, visit-www.vavaclasses.com
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.
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.
4. •Democritus (400 B.C.)
• Proposed that matter was
composed of tiny indivisible
particles
• Philospher; Not based on
experimental data.
• Greek: atomos
5. •John Dalton (1807)
• British Schoolteacher
• Dalton’s postulate
• Proposed Ball Model
• atom is a
uniform,
solid sphere
6. •J. J. Thomson
• Cathode Ray Tube
Experiments
• beam of negative
particles
• Discovered Electrons
• negative particles within
the atom
• Plum-pudding Model
7. •Thomson’s Cathode Ray Experiment
Stream of electrons is attracted to positively charged plate here.
"
8. •J. J. Thomson
Plum-pudding Model
• positive sphere
(pudding) with
negative electrons
(plums) dispersed
throughout
9. •Ernest Rutherford
Student of J.J THOMSON
Nobel prize winner.
Rutherford performed the famous
‘GOLD FOIL EXPERIMENT’.
Discovered NUCLEUS :dense, positive
charge in the center of the atom.
Proposed NUCLEAR MODEL
15. •Niels Bohr • Father of QUANTUM
PHYSICS
• Revised RUTHERFORD’S
model .eletron is
accelerating charge.
• Energy Levels
• electrons can only exist
in specific energy states
16. • Bright-Line Spectrum :
• tried to explain presence
of specific colors in
hydrogen’s spectrum
• Planetary Model
• electrons move in circular
orbits within specific
energy levels
Bright-line spectrum
17. •Erwin Schrödinger :
Electron Cloud Model (orbital)
• dots represent probability of finding an e-
not actual electrons
18. ELECTRON CLOUD Model
This model is based
upon Bohr’s model,
except that electrons
orbit the nucleus in
random patterns. The
region where these
particles are found is
referred to as the
electron cloud.
Electron Clouds
Nucleus
19. • The Nucleus and Structure of the
Atom
• Atoms are made of three kinds of
particles: electrons, protons, and
neutrons.
20. • The structure of the atom
• The protons &
neutrons are present
in nucleus
• Electrons are
outside the nucleus
in the electron
cloud.
22. Nomenclature for Elements
"X" = Element Symbol
"Z" = ATOMIC NUMBER: no.of Protons
Each eleMenT has a unique "Z”
"N” = no.of Neutrons
"A" = ATOMIC MASS:no.of neutron +proton ( A = Z + N)
ISOTOPE: Atoms of same elements with same
atomic no. but different mass no.
Isobar: ATOMS OF DIFFERENT ELEMENT HAVING SAME
MASS NO. BUT DIFFERENT ATOMIC NO.
X
A
Z
24. • The strong nuclear force attracts
neutrons and protons to each other,
otherwise the positively charged protons
would repel each other.
25. • Electrons are bound to the
nucleus by
electromagnetic forces.
• The force is the attraction
between protons
(positive) and electrons
(negative).
The momentum of the electron causes it to move
around the nucleus rather than falling straight in.
26. 26
• As a general rule, a
nucleus will need a
neutron/proton ratio
of 3:2 (or 1.5:1) in
order to stay
together.
27. 27
As atomic mass increases,
the neutron to proton ratio for
stable nuclei increases
because proton-proton
repulsion becomes significant!!!
Nuclear forces arise form
neutrons, so the neutron to
proton ratio must increase for
heavier elements.
Belt of Stability
Proton number, Z
Neutronnumber,N=A-Z
N = Z
For helium He- 4 the N:P ratio is 1 : 1
For uranium U- 238 the ratio is 1 : 1.6
28. • If an isotope has too many (or too few)
neutrons, the nucleus eventually breaks up
and we say the atom is radioactive.
• In a stable isotope the nucleus stays
together.
29. 29
• The amount of
energy that keeps a
nucleus together is
called the Binding
Energy.
• This amount of
energy is higher for
nuclei that are stable
than it would be for
unstable nuclei.
30. 30
Mass Defect
The difference
between the mass
of the atom and
the sum of the
masses of its parts
is called the mass
defect (Dm).
measurements show that the mass of a particular atom is always
slightly less than the sum of the masses of the individual protons,
neutrons and electrons of which the atom consists.
e.g. a helium nucleus consists of 2 protons and 2 neutrons
2 protons & 2 neutrons Helium atom
31. 31
Mass defect can be converted into equivalent energy called as binding energy.
Using Einstein’s E = mc2, this is equivalent to a loss of energy
This figure is the BINDING ENERGY .
THE BINDING ENERGY of a nucleus is defined as the energy which must be input
to separate all of its protons and neutrons.
32. 32
Binding Energies are usually expressed in MeV
1 amu = 931.3 MeV
To compare the stabilities of different nuclei,
Binding Energies PER NUCLEON in the nucleus are compared.
The higher the binding energy per nucleon,
the greater the stability of the nucleus
34. 34
FISSION
IRON
Heavy nuclei may increase their stability by Nuclear Fission
Light nuclei may increase their stability by Nuclear Fusion
FUSION
35. 35
Nuclear Fission is the fragmentation of heavy nuclei to form lighter, more stable ones.
The Fission of U - 235
U235
92
energyofMeVnKrBanU 18031
0
94
36
139
56
1
0
235
92
This is only one of several fissures that are possible.
On average 2.5 neutrons are released
36. 36
Critical mass :is the mass required for the
chain reaction to become self-sustaining.
neutron
Some neutrons may :
Cause
more
fission
Get
lost
Be
absorbed
by an atom
lost
For a chain reaction to be self sustaining,
every fission must produce at least one more
neutron that will initiate further fissions.
37. Every good conversation starts with good
listening.
Thankyou verymuch for ur patient listening.
Special thanxs to S.PMISHRA SIR for his
guidance and support.