AnswersChemistry - SC3210 A-CRUnit Test

Unit Test — Unit test Answers

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1
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Which element is the most reactive?

A
sodium
B
nickel
C
carbon
D
oxygen
2
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Which element is classified as an alkali metal?

A
Rb
B
Sr
C
Zr
D
Cl
3

What did Ernest Rutherford’s gold foil experiment demonstrate about an atom?

A
Each atom is composed of electrons and positive material.
B
The mass of the atom is evenly spread throughout the atom.
C
Neutrons are located in the center of the atom.
D
Positive charge occupies a very small volume in the atom.
4

Which scientist is known for developing the planetary model of the atom?

A
Niels Bohr
B
Albert Einstein
C
Johannes Rydberg
D
Robert Millikan
5

Which of the following symbols would be included in the noble gas notation for an element that had valence electrons in the 5s subshell?

A
Ar
B
Kr
C
Xe
D
Rn
6

How many valence electrons does aluminum (Al) have available for bonding?

A
1
B
2
C
3
D
4
7

Which set of numbers gives the correct possible values of l for n = 2?

A
0
B
0, 1
C
0, 1, 2
D
0, 1, 2, 3
8

To show the electron configuration for an atom, when would it be better to use an orbital notation than to use a written configuration with numbers, letters, and superscripts?

A
when the aim is to use less space
B
when the aim is to show electron spins
C
when the aim is to show orbital shapes in subshells
D
when the aim is to show electron distributions in shells
9

Which element has the largest atomic radius?

A
As
B
N
C
P
D
Sb
10

Hydrogen has three isotopes 1H, 2H, and 3H. What is the difference between these three isotopes?

A
The number of protons ranges from 1 to 3.
B
The number of electrons ranges from 1 to 3.
C
The number of neutrons ranges from 0 to 2.
D
The number of protons ranges from 0 to 2.
11

How did Niels Bohr describe electrons in his atomic model?

A
Their energies can have any values.
B
Their exact positions cannot be known.
C
They have high probability to be found in certain regions.
D
They orbit the central nucleus in discrete paths.
12

Which of Dalton's ideas about the atom did J.J. Thomson's experiment disprove?

A
It disproved that atoms are divisible.
B
It disproved that atoms are indivisible.
C
It disproved that atoms contain protons.
D
It disproved that atoms contain electrons.
13

The diagram below shows some subatomic particles.Which of these statements best identifies the particle that is labeled with an X?

Question illustration
A
It is either a nucleus or a proton.
B
It is either a proton or a neutron.
C
It is either a neutron or an electron.
D
It is either an electron or a nucleus.
14

Among the elements of the main group, the general trend in the first ionization energy moving across a period is not followed between group 2 and group 13. Which best explains these exceptions?

A
The ionization energy decreases because the full s orbital shields the electron entering the p orbital.
B
The ionization energy increases because the full s orbital shields the electron entering the p orbital.
C
The ionization energy decreases because the stability of the half-full p subshell is increased.
D
The ionization energy increases because the stability of the half-full p subshell is increased.
15

A single atom of an element has 11 protons, 11 electrons, and 12 neutrons. Which element is it?

A
V
B
Na
C
Mg
D
Se
16

The elements of which group are nonreactive?

A
halogens
B
alkaline earth metals
C
noble gases
D
alkali metals
17

Which characteristic is given by the angular momentum quantum number?

A
orbital size
B
orbital mass
C
orbital shape
D
orbital orientation
18

Which element has 32 protons in its nucleus?

A
phosphorus
B
cobalt
C
germanium
D
sulfur
19

In which orbitals would the valence electrons for selenium (Se) be placed?

A
s orbital and f orbital
B
s orbital only
C
s orbital and p orbital
D
d orbital only
20

Which statement best describes how electrons fill orbitals in the periodic table?

A
Electrons fill orbitals in order of their increasing energy from left to right.
B
Electrons fill orbitals in order of their increasing energy from right to left.
C
Elements fill orbitals in order of increasing energy from top to bottom in each group.
D
Elements fill orbitals in order of increasing energy from bottom to top in each group.

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