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Atomic Study Guide - CP Chemistry - KEY
1. Complete the following table:
Element
Symbol
Atomic #
Mass #
# of
protons
# of
electrons
# of neutrons
scandium
Sc
21
45
21
21
24
rhodium
Rh
45
103
45
45
58
mercury
Hg
80
201
80
80
121
chlorine
Cl
17
35
17
17
18
2. Complete the following table:
Isotope
Symbol
Atomic #
Mass #
# of
protons
# of
electrons
# of
neutrons
selenium-79
79
Se
34
79
34
34
45
rubidium-85
85
Rb
37
85
37
37
48
Pd
46
107
46
46
61
107
palladium-107
3. Complete the following table:
element name
symbol & charge
of ion formed
ion name
Cation (+) or
anion (-)?
Metal or
nonmetal?
potassium
K+
potassium ion
cation
metal
sulfur
S2-
sulfide ion
anion
nonmetal
bromine
Br-
bromide ion
anion
nonmetal
iron
Fe3+
iron ion
cation
metal
4. True/False: Write the letter T or F in the space provided by each statement.
F Atoms of the same element have the same number of neutrons in the nucleus.
T The mass of a proton is approximately equal to the mass of a neutron.
T Atoms of the same element have the same number of protons in the nucleus.
T Atoms of elements are electrically neutral.
F The mass of an electron is approximately equal to the mass of a neutron.
F When an electron is excited it travels to a higher energy level. When it falls back down it releases a
proton.
5. Explain the contribution to the scientific community made by each individual listed below:
a.) Democritus – first theorized concept of atom (“indivisible units” of matter)
b.) Thompson and Millikan – discovered electrons
c.) Rutherford – discovered positively charged nucleus
d.) Bohr – solar system model of atoms, energy levels at increasing distance from nucleus
e.) Mendeleev – first periodic table of elements
f.) Moseley – today’s periodic table (arranged by atomic number)
6. Evaluate each part of Dalton’s Atomic Theory listed below. State which points are still completely supported by
the scientific community today, and explain why some of the points were disproved or clarified.
a.)
b.)
c.)
d.)
All elements are made of tiny atoms.
Completely supported
Atoms cannot be subdivided. Atoms can be subdivided (protons, neutrons, electrons, etc.) but particles do not retain
properties of the element
Atoms of the same element are exactly alike. Atoms of same element are similar, but can have different numbers of
neutrons (isotopes)
Atoms of different elements can join to form molecules. Completely supported
7. Write the complete and abbreviated electron configurations for the following atoms and ions:
a.)
Mg
1s22s22p63s2
[Ne]3s2
b.)
Mg2+
1s22s22p6
[Ne]
c.)
Mn
1s22s22p63s23p64s23d5
[Ar] 4s23d5
8. Draw the orbital diagram and the Lewis dot diagram for the following elements:
a) He

He – two dots to the right
1s
b)
Si
      _ _ __
1s 2s
2p
3s
3p
Si – four dots – 2 right, 1 up, 1 left
c)
O
   _ _
1s 2s
2p
O – 6 dots – 2 right, 2 up, 1 left, 1 down