Download Test Review with answer key and explanations

Atomic Structure and Periodic Table
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1. An unidentified element has many of the same physical and chemical properties
as iodine and chlorine but has a lower atomic mass than either of those elements.
What is the most likely identity of this element?
A
fluorine
B
bromine
C
sulfur
D
astatine
2. What are some properties and characteristics of the 18th group on the periodic
table, otherwise known as noble gases?
3. According the periodic table, which element is highly conductive of heat and
electricity?
A
Silicon
B
Argon
C
Fluorine
D
Copper
4.
What are some properties and characteristics of Group 2?
5. The bonding characteristics of fluorine are most similar to the bonding
characteristics of
A
bromine
B
oxygen
C
arsenic
D
neon
6.
Which group has a metal, a nonmetal, and a metalloid?
A
silicon, iodine, antimony
B
magnesium, calcium, lithium
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C
aluminum, arsenic, and xenon
D
oxygen, bromine, and iron
7.
this picture shows a model of the element
A
chlorine
B
helium
C
lithium
D
magnesium
8.
What are some properties and characteristics of group 1 elements?
9.
How do you find the number of neutrons in an atom?
10.
Which of the following elements is the best conductor of heat?
A
oxygen
B
chlorine
C
argon
D
gold
11. This table shows the atomic radii (size) of some elements on the periodic table.
Which inference can be made from this information?
A
Atomic radii increases from left to right.
B
Atomic radii decreases from right to left.
C
Atomic radii increases from top to bottom
D
Atomic radii double from top to bottom
12. A mercury atom has an atomic number of 80 and a mass number of 202. How
many protons, electrons, and neutrons does this atom have?
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13. A certain atom has a nucleus containing 20 protons, 22 neutrons, and 20
electrons. This atom is a form of which element?
14.
A neutral atom
A
has gained or lost electrons
B
has more neutrons than protons
C
has a positive or negative charge
D
has the same number of of protons and electrons
15. Which of the following groups contain members with similar chemical
reactivity?
A
Mg, N, Ba
B
Se, S, O
C
Fe, Ru, Rh
D
P, S, Cl
16. Which statement is false regarding atoms?
A
Atoms contain protons and neutrons in their nucleus.
B
Atoms of the same element contain the same number of protons and neutrons
C
Atoms can gain or lose electrons because they are located outside of the nucleus.
D
Atoms with metallic properties usually tend to lose electrons.
17.
At STP, which element is solid, brittle, and a poor conductor of electricity?
A
Al
B
N
C
Co
D
Na
18.
How many valence electrons does Phosphorous (P) have?
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19.
What charge will an ion of oxygen form according the periodic table.
20. Which location on the periodic table would you find an element that will gain
two electrons?
21.
Which group has the most reactive metals?
22.
How many valence electrons does Krypton have?
23.
How many electrons does oxygen lose or gain?
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Answer Key and Explanations
1. Fluorine
Elements in the same group (vertical columns on the periodic table) have similar
physical and chemical properties. The higher up on the periodic table something is, the
lower the atomic mass.
2. The elements of group 18 are inert and unreactive because they have 8 valence
electrons. This full orbital means they do not react with other elements.
3. Copper
Copper is the only metal listed. Metals are elements to the left of the staircase on the
periodic table.
4. Group 2 has two valence electrons and are likely to lose both of those electrons when
forming ions. It is a metal and that makes it conductive. It is reactive.
5. Bromine
Bromine and fluorine are in the same group on the periodic table.
6. Aluminum, arsenic, and xenon
Aluminum is a metal (it’s the only atom around the staircase that isn’t a metalloid),
arsenic is a metalloid because it’s on the staircase, xenon is a nonmetal because it is to
the right of the staircase.
7. Lithium
There are three protons in the picture. Lithium is the element with the atomic number
of 3
8. Group 1 elements are very reactive because they are close to having full orbitals. They
just need to lose one electron to get a full orbital. They are also metals because they
are to the left of the staircase.
9. Neutrons = mass number – atomic number
or neutrons = mass number – protons
10. Gold
Gold is the only metal listed. Metals are to the left of the staircase. Metals conduct
heat better than metalloids or nonmetals.
11. Atomic radius increases as you go from the top to bottom and right to left. The largest
radius would be at the bottom left hand corner and the smallest radius would be close
to the top right corner.
12. 80 protons, 80 electrons, 202 neutrons
The atomic number shows the number of protons that the atom has. So since the
atomic number is 80, there are 80 protons. In a neutral atom (as opposed to an ion) the
number of electrons and protons are the same, so that means there are 80 electrons as
well. To find the neutrons you subtract mass number – atomic number, so in this case
202 – 80 gives you 122 neutrons.
13. Calcium (Ca)
The atomic number on the periodic table equals the number of protons. So an atom
with 20 protons has an atomic number of 20. The element with the atomic number of 20
on the periodic table of elements is calcium.
14. Has the same number of protons and electrons
An atom being neutral means that the charge is 0. Since protons have a positive
charge and electrons have a negative charge, in order to have a charge of 0, the
neutral atom has to have the same number of protons and electrons.
15. Se, S, O. Groups (vertical columns on the periodic table) have similar chemical
reactivity. Of these lists, only Se, S, and O are all in the same group (group 16) on the
periodic table. P, S, and Cl are all the same period on the periodic table, but periods do
not have similar chemical reactivity.
16. Atoms of the same element contains the same number of protons and neutrons.
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Atoms of the same element always contain the same number of protons. However
there are isotopes, which are atoms of an element with different number of neutrons
from each other. Protons and neutrons are in the nucleus. Electrons are outside of the
nucleus making it easier to gain or lose electrons, and atoms with metallic properties
usually tend to lose electrons because they are on the left side of the periodic table and
tend to have fewer electrons in their orbitals.
17. N
solid, brittle, and being a poor conductor are all properties of a nonmetal. Nonmetals
are elements on the right side of the staircase on the periodic table. N is the only
nonmetal answer.
18. 5
You can tell how many valence electrons are in an element by looking at the last digit of
the group number, Phosphorous is in group 15 on the periodic table so it has 5 valence
electrons.
19. -2 or 2Atoms want to have 8 valence electrons when they form their ions. Since oxygen is in
the 16th group, it has 6 valence electrons as an atom. It wants to gain 2 more. Electrons
are negative that makes the charge -2. You can also memorize what ions will be made
by each group. All group 16 ions can make a -2 ion.
20. Group 16.
See explanation for 19.
21. Group 1
Metals become more reactive as they move left on the periodic table. Since group 1 is
the group on the very left on the periodic table, it is the most reactive.
22. 8
Krypton is in group 18. Group 18 atoms have 8 valence electrons.
23. +3
Nitrogen has 5 valence electrons. It gains 3 to get a total of 8.
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