Atomic Theory Quiz 2 Flashcards

Terms Definitions
Discovered electrons
discovered electrons
J.J. Thomson
Cathode ray
Gold Foil Experiment
who discovered x-rays?
law of definite
Atomic Number
Number of Protons
Modern day Atomic Model
J.J. Thompson
Plum Pudding atom
law of definite proportions
pure elements
Gold, silver, carbon (diamond)
Niels Bohr
Danish-1913-model showed that electrons move in specific layers
positively charged in the nucleus
anything with mass and volume
Energy levels with orbiting electrons
Electrons and Positively Charged Material Spread Randomly throughout the Atom
the subunit of nucleic acid
LAW OF DEFINITE PROPORTIONS - (elements that compose compounds were always in certain proportion by mass and in a chemical formula you always have a set ratio)
discover that elements can be fingerprinted according to their spectra
(chemistry) a substance formed by chemical union of two or more elements or ingredients in definite proportion by weight
quantitative work with electricity and solutions-Particular atoms and ions gain or lose a specific number of electrons.
helps make the Thomson Theory
smallest particle into which an element can be divided and still be the same substance
Noble Gases
Contains nonmetals that are unreactive. Full outermost energy level except helium which has 2.
Electron Configuration
2= principal energy level
p= type of orbital
⁶= number of electrons in sublevel orbitals
Remember to sum the superscripts in the electron configuration. They should add up to the atomic number for the element.
Aufbau principle
Electrons will always occupy the lowest energy level available (while at ground state).
True or false: Dalton's Atomic Theory had the idea that atoms contain electrons, protons, and neutrons.
Gamma rays
high-energy radiation that possess no mass and electric charge
Electron Shell
a grouping of electrons surrounding the nucleus of an atom
J.J. Thomson (1897)
Discovered the electron; Determined the charge-to-mass ratio of electrons; "plum pudding model"
Mass Number/Atomic Number followed by Element
(40/19 K)
Nuclear Notation
alpha particles
helium nuclei emitted from a radioactive source
Taught the concept of the four elements. Created the Empedocles square
Ernest Rutherford
Who created the gold foil experiment?
Says bohr can't be right- Unsertainty Principle (we aren't good enough to tell exactlyu where e are
Democritus (~400 B.C.E)
Greek philosopher
All matter composed of small, indivisible particles ("atomos"=atoms)
Idea not widely accepted
energy levels
Each element has a discrete number, numbered with whole numbers and divided into sublevels.
an atom where the total number of electrons is not equal to the total number of protons
A ray of radiation that originates from the cathode and travels to the anode of a cathode ray tube.
Cathode ray
is an unifying explantion for a broad range of hypotheses adb observations that have been supported by testing
Atomic Theory
atoms are the building blocks of matter and that different types of atoms exist for different types of matter
atomic mass
decimal number on the periodic table; tells us the number of protons and neutrons (A)
no charge, same mass as proton 1 amu
Diffraction grating
A sheet of plastic into which thousands of parallel prisms have been engraved.
Valence electrons
Electrons which actually take part in chemical change
P orbital
6 electrons in each orbital. = Row
These are located in the nucleus. They have no electrical charge, but add to the mass of the atom
Alpha Decay
Mass number is reduced by 4. Subtract 2 protons.
an atom that has thhe same # of protons or same atomic #as other atoms
daltons first assumption
all matter is made up of atoms
Leo Szilard
-use Han and Meitner research as a base
-discovered neutron multiplication in uranium
-proving a chain reaction possible and nuclear weapons possible
-made the first human controlled chain reaction
John Dalton
father of modern chemistry and of the theory of matter
Transmutation of Elements
Transmutation of an element can occur spontaneously or artificially.
electron cloud
a region around the nucleus of an atom where electrons are likely to be found.
a region in an atom where there is a high probability of finding electrons
Covalent Molecule
A group of atoms in which the atoms are bound together by sharing one or more pairs of electrons
Dalton's Atomic Theory
1. All matter is made of indivisible particles called atoms
2. Atoms of a given element are all identical in size and mass but differ in size and mass from atoms of different elements
3. Atoms cannot be subdivided, created or destroyed
4. Atoms combine to make chemical compounds in simple, whole numbers
5. In chemical reactions, atoms are only combined, separated or rearranged
Thompson and Rutherford
Whose 2 Atomic Models look exactly the same
what is a neutron?
Particle in the nucleus of an atom with no charge.
gases, brittle or powdery solids (except bromine-liquid)
nonmetals are usually _________ or ______________ at room temperature
the three dimensional wave mode of the atom
Erwin Schrodinger made what?
Who discovered electrons and what are they?
Joseph John Thomson; they are negatively charged particles.
Atomic theory of matter
1. All matter is made up of atoms
2. Atoms are individual and invisible
3. All atoms of one element are exactly alike but different from other elements
4. His concept is called the solid sphere model
How many electrons will completely fill an s subshell?
A maximum of two electrons can reside in an s subshell; however, these electrons must have opposite spins.
Open empty space and positive charge in nucleus
What does this diagram prove about the structure of the atom?
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