Who was John Dalton?
When did he propose his model of the atom?
What was his model of the atom called?
Describe his model of the atom.
Scientist, school teacher
early 1800s (1803)
Cannonball
Atom is a hard sphere
100
What are the 3 subatomic particles?
What are their charges?
Where are they located in the atom?
Proton, Neutron, Electron
Proton = +1, Neutron = 0, Electron = -1
Proton+Neutron = in nucleus, Electron = surrounding nucleus
100
What are PURE SUBSTANCES?
elements & compounds
100
Why are atoms neutral?
# of protons = # of electrons
100
How do you find the number of neutrons in an atom?
# of n = mass # - atomic #
200
Who was JJ Thomson?
When did he propose his model of the atom?
What was his model of the atom called?
Describe his model of the atom.
Scientist
late 1800s (1897)
Plum Pudding
Atom is a positively charged sphere with negatively charged electrons uniformly spread throughout.
200
What was the first subatomic particle discovered?
Who discovered it?
Electron
JJ Thomson
200
What is the difference between an ELEMENT and a COMPOUND?
Elements are substances that cannot be broken down or decomposed into simpler substances.
Compounds are composed of two or more elements that are chemically combined in definite proportions by mass.
200
What is the NUCLEAR charge of a phosphorous atom?
+15
200
Boron-10 and Boron-11 are naturally occurring isotopes of elemental Boron. If Boron has an atomic mass of 10.81 amu, which isotope occurs in greater abundance?
B-11 must occur in greater abundance because the atomic mass of Boron is much closer to B-11 than to the mass of B-10.
300
Who was Ernest Rutherford?
When did he propose his model of the atom?
What was his model of the atom called?
Describe his model of the atom.
Scientist
early 1900s (1909)
Nuclear Model
Nucleus is the small dense core and it is surrounded by negatively charged electrons
300
What did Millikan discover?
Electron has charge of -1 and a mass of 9.11X10^-27kg
300
What is the difference between a COMPOUND and a MIXTURE?
A compound has a definite proportion while a mixture has a varying proportion.
300
What is the charge of a carbon atom?
0; all atoms are neutral
300
How many electrons, protons, and neutrons are contained in each atom?
a)Cs-132
b)Co-59
c)Tm-163
d)Zn-70
a) 55e, 55p, 77n
b) 27e, 27p, 32n
c) 69e, 69p, 94n
d) 30e, 30p, 40n
400
Who was Niels Bohr?
When did he propose his model of the atom?
What was his model of the atom called?
Describe his model of the atom.
Scientist
early 1900s (1913)
Planetary Model
Nucleus is in the center and the electrons orbit around the nucleus in fixed pathways
400
What were the 2 major conclusions of the Gold Foil Experiment?
1. Atoms are mostly empty space
2. Atoms have a dense, positively charged core
400
List the diatomic molecules.
HOClNBrIF
H = hydrogen
O = oxygen
Cl = chlorine
N = nitrogen
Br = bromine
I = iodine
F = fluorine
400
What tenets of Dalton's theory were found to be incorrect? Explain why they were incorrect.
1. Atoms are indivisible - wrong: atoms are comprised by subatomic particles
2. All atoms of a given element have the same mass - wrong: isotopes
400
How do you calculate atomic mass?
(mass)(% abundance) + (mass)(% abundance) + ...
500
What is the Present Day model of the atom?
Describe this model of the atom.
Wave-Mechanical / Electron Cloud
Atom has a dense, positively charged nucleus with electrons found in regions of probable location.
500
What are:
mass number?
atomic number?
atomic mass?
isotopes?
mass # = # of protons + neutrons
atomic # = # of protons
atomic mass = weighted average of naturally occurring isotopes for a given element
isotopes = atoms of a give elements that have different mass numbers (as a result of having different numbers of neutrons)
500
Convert 800mg into kg.
0.0008kg
500
What are the 3 types of radiation?
Why is the charge of each type of radiation?
What will each type of radiation be attracted to?
Alpha, beta, gamma
Alpha = +2, beta = -1, gamma = 0
Alpha attracted towards negative charge; beta attracted towards positive charge; gamma will not be attracted