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... • Knowing that light has a particle nature, it seems reasonable to ask if matter has a wave nature. • Using Einstein’s and Planck’s equations, de Broglie h showed: l mv • The momentum, mv, is a particle property, whereas l is a wave property. • de Broglie summarized the concepts of waves and partic ...
Atoms and Bonding
Atoms and Bonding

... • If two isolated atoms are brought closer together the net force varies with distance  there is a mechanism-specific attractive force (FA)  and a repulsive force (FB), which increases when the atoms are sufficiently close for the outer shells to overlap  equilibrium is reached when FA + FB = 0  ...
Chapter 8 - Bakersfield College
Chapter 8 - Bakersfield College

... 1. Ruby lasers use xenon-filled flash lamps to excite chromium ions in ruby rods. 2. Helium-neon lasers use an electric discharge to bring the atoms of the gas mixture to metastable levels. D. The metastable atoms, as they return to their ground states, create photons all of the same frequency and a ...
Grade 10 NSC Chemistry Curriculum
Grade 10 NSC Chemistry Curriculum

... Students should develop an understanding about the importance of the periodic table in Chemistry. Knowledge and concepts about periodic trends of physical properties of some elements are required • Understand that elements in the PT are arranged in order of ascending atomic number • Appreciate the P ...
APCh7MB
APCh7MB

... Δ x = uncertainty in the particle’s position Δ (mv) = uncertainty in particle’s momentum h = Planck’s constant Smallest possible uncertainty = h/4π (h/4π)2 = probability distribution Radius of the sphere encloses 90% of the total electron probability ...
Dmitri Mendeleev
Dmitri Mendeleev

... Z = 17 # of neutrons = 18 (35 - 17) ...
Outline Chapter 10 The Periodic Law
Outline Chapter 10 The Periodic Law

Particles and Waves Answers
Particles and Waves Answers

... energy of which is dependent on the frequency of the photon. The photon energy can be calculated using the equation E = hf. Below a certain frequency the energy absorbed by an electron in the metal, from the photon, is below that required to escape from the metal atom, thus the current in the circui ...
Chapter Summary
Chapter Summary

... In our modern view of the atom, the nucleus is modeled as a point particle with a positive charge. The chemical properties of the atom are dominated by the behavior of the atom’s electrons. In contrast to the popular representation of an atom being made up of a positive nucleus orbited by electrons ...
Widener University Summer 2004 ENVR 261 Modern Physics Name
Widener University Summer 2004 ENVR 261 Modern Physics Name

... Why is the direction of the orbital angular momentum of an electron opposite that of its magnetic moment? ...
Quantum Science for Energy Healers
Quantum Science for Energy Healers

... Topic
G:
Review
of
Week
1:

 G:1
key
concepts
learned
in
week
1.
 a)
all
matter—both
living
and
“non‐Living”‐‐
is
composed
of
atoms.
 b)
atoms
have
a
dense,
positive
core
containing
protons
and
neutrons
with
 negatively
charged
electrons
located
outside
the
nucleus.


 c)
electrons
can
be
removed
an ...
The Quantum Mechanical Model of the Atom
The Quantum Mechanical Model of the Atom

... • H is set of mathematical instructions called an operator that produce the total energy of the atom when they are applied to the wave function. • E is the total energy of the atom (the sum of the potential energy due to the attraction between the proton and electron and the kinetic energy of the mo ...
CHEM121 Lecture Ch5 student
CHEM121 Lecture Ch5 student

... How much carbon dioxide (in grams) is produced when 3.00 g of ethanol (C2H6O) combusts in air? How much oxygen gas is used up to combust 5.00 g of ethanol? ...
Modern Physics - Politechnika Wrocławska
Modern Physics - Politechnika Wrocławska

... photon cannot give enough energy to the electron to leave the surface Kmax does not depend on light intensity, because doubling the number of photons would only double the number of electrons and not double their energy Kmax increases with frequency because energy and frequency are related If light ...
Bohr, Niels Henrik David
Bohr, Niels Henrik David

The birth of quantum mechanics
The birth of quantum mechanics

(Electrostatics) Posted 07/15/2005
(Electrostatics) Posted 07/15/2005

... 6.) An electron is accelerated eastward at 1.8 x 109 m/s2 by an electric field. Determine the magnitude and direction of the electric field. Where is it 1.50 s later? 7.) Calculate electric field, E, at point P(0.5,0.5) if a charge q1 = q is placed at (1,0), q2 = 2q is placed at (0,0),and q3 = q is ...
Multi-Particle States 31.1 Multi
Multi-Particle States 31.1 Multi

Chem 152 Chapter 4
Chem 152 Chapter 4

... • Elements are the most basic form of matter. • Cannot be broken into simpler substances by chemical or physical processes. • A sample of an element contains only one type of atom. • There are over 100 known elements. ...
word-doc Practice for the final exam!
word-doc Practice for the final exam!

Electromagnetic Spectrum activity
Electromagnetic Spectrum activity

... This states that no two electrons in any atom have the same amount of energy associated with it and therefore cannot follow the same path. Therefore considering the first energy level, n= 1 ( n is the first quantum number), contains 2 electrons (maximum) these electrons have different spins :- one c ...
Lecture 11 Atomic Structure Earlier in the semester, you read about
Lecture 11 Atomic Structure Earlier in the semester, you read about

... associated with allowed quanta of energy leaving the atoms. For example, the yellow light emitted by sodium with a wavelength of 589 nm, corresponds to a frequency of: c = λν = 2.998 x 108 m s-1 ν = 2.998 x 108 m s-1 ÷ 589 x 10-9 m = 5.09 x 1014 s-1 Substituting this value into Planck's equation giv ...
Lecture 9 - MIT OpenCourseWare
Lecture 9 - MIT OpenCourseWare

... which is called the principal quantum number. 2. Since the energy levels and radial decay rate depend only on the n number this�number is used to identify an electron shell. 3. For each energy En , there exist several values of l:�l=0,...,n–1. This means that there are more than one eigenfunction ...
AS Chemistry - Crawshaw Academy
AS Chemistry - Crawshaw Academy

Practice exam - Dynamic Science
Practice exam - Dynamic Science

... The smallest particle of matter. The smallest possible sugar crystal. The smallest particle of water. The energy given off during a chemical reaction. ...
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Atomic theory



In chemistry and physics, atomic theory is a scientific theory of the nature of matter, which states that matter is composed of discrete units called atoms. It began as a philosophical concept in ancient Greece and entered the scientific mainstream in the early 19th century when discoveries in the field of chemistry showed that matter did indeed behave as if it were made up of atoms.The word atom comes from the Ancient Greek adjective atomos, meaning ""uncuttable"". 19th century chemists began using the term in connection with the growing number of irreducible chemical elements. While seemingly apropos, around the turn of the 20th century, through various experiments with electromagnetism and radioactivity, physicists discovered that the so-called ""uncuttable atom"" was actually a conglomerate of various subatomic particles (chiefly, electrons, protons and neutrons) which can exist separately from each other. In fact, in certain extreme environments, such as neutron stars, extreme temperature and pressure prevents atoms from existing at all. Since atoms were found to be divisible, physicists later invented the term ""elementary particles"" to describe the ""uncuttable"", though not indestructible, parts of an atom. The field of science which studies subatomic particles is particle physics, and it is in this field that physicists hope to discover the true fundamental nature of matter.
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