Scientists
Who discovered the electron?
Thompson
What experiment led to the discovery of the electron?
cathode ray tube
Has a charge of -1
electron
C
A#:6
M#:12
p:6
n:6
e:6
What are the units of average atomic mass
amu (atomic mass units)
Who was the first to use the term "atom"
Democritus
What experiment led to the discovery of the nucleus
gold foil experiment
Has no charge
neutron
Al-30
A#:13
M#:30
p:13
n:17
e:13
An atom has 3 isotopes. One has a % abundance of 54.2%. One has a % abundance of 13.7%. What is the % abundance of the third isotope?
32.1%
Who did the gold foil experiment
Rutherford
How did Thompson know electrons had a negative charge?
used a magnet
Has a charge of +1
proton
Se-2
A#:34
M#:79
p:34
n:45
e:36
Calculate the AAM of Mn:
Mn-52: Mass=51.934 amu, 60.0% abundance
Mn-56 Mass=56.002 amu, 40.0 % abundance
53.561 amu
Explain what is the chocolate chip cookie model and who proposed it
Electrons are the chocolate chips, the cookie dough is an unknown positive matter. Both are evenly distributed throughout the atom. Proposed by Thompson.
Explain the gold foil experiment
Radiation is shot at a piece of gold foil. Rutherford expects the high energy radiation to go right through. However, some radiation begins to reflect to the side and even come backwards. Radiation must be hitting something really small and really dense. This is determined to be the nucleus
Makes up the nucleus (2 things)
Protons and neutrons
V-48
A#:23
M#:48
p:23
n:25
e:23
Calculate the AAM of O:
O-16: Mass=16.121 amu, 95.0 % abundance
O-15 Mass=15.025 amu, 5.0 % abundance
16.066 amu
Dalton's atomic theory had 5 parts. List all 5.
1. All elements made of atoms
2. All atoms of the same element are identical
3. Atoms cannot be created or destroyed
4. Different atoms can combine to make compounds
5. Atoms rearrange in chemical reactions
Explain the cathode ray tube experiment
All air removed from a tube, plates on either end are connected to a battery to create a beam of electrons in the tube, positively charged magnet is used to determine the negative charge of the electrons.
Has almost no mass
electrons
Au+2
A#:79
M#:197
p:79
n:118
e:77
Calculate the AAM of P:
P-33: Mass=32.955 amu, 21.0% abundance
P-30 Mass=29.994 amu, 79.0% abundance
30.616 amu