Question 1

Which of the following electron configurations is impossible?
A) 
B) 
C) 
D) 
E)

Accepted Answer

The electron configuration given in option A is not possible because it includes letters and underscores, which are not part of electron configurations. A valid electron configuration should only include numbers and the symbols representing the energy levels and sublevels.

Question 2

Given the following: Which are isotopes of each other?
A)  are isotopes of each other.
B)  are isotopes of each other; and  are isotopes of each other.
C)  are isotopes of each other.
D)  are isotopes of each other.

Accepted Answer

The answer of Given the following: Which are isotopes of...

Question 3

Chlorine has two naturally occurring isotopes. The isotope Cl-35 (mass = 35.0 amu)makes up 75.8% of the sample, and the isotope Cl-37 (mass = 37.0 amu)makes up 24.2% of the sample. What is the average atomic
Mass for chlorine?
A)36.6 amu
B)35 amu
C)36.0 amu
D)35.521 amu
E)35.5 amu

Accepted Answer

The answer of Chlorine has two naturally occurring isotopes. The...

Question 4

The number of electrons in the outer energy level of a neutral atom of boron (atomic number 5)is
A)2.
B)3.
C)5.
D)8.
E)10.

Accepted Answer

Boron has 5 electrons, arranged in the electron configuration 1s²2s²2p¹. The outermost energy level (valence level) is the 2nd energy level, which contains 3 electrons in the 2s and 2p orbitals. Therefore, the number of electrons in the outer energy level of a neutral atom of boron is 3.

Question 5

What is the electron configuration for aluminum?
A) 
B) 
C) 
D) 
E)

Accepted Answer

The answer of What is the electron configuration for aluminum?
A)...

Question 6

The number of orbitals in the 4d sublevel is
A)1.
B)2.
C)3.
D)4.
E)5.

Accepted Answer

The 4d sublevel, like all d sublevels, contains 5 orbitals. This is because d orbitals are made up of five orientations: dxy, dyz, dxz, dx2-y2, and dz2.

Question 7

What is the abbreviated electron configuration for nickel (atomic number 28)?
A) 
B) 
C) 
D) 
E)

Accepted Answer

The answer of What is the abbreviated electron configuration for...

Question 8

What element has the electron configuration 
A)carbon
B)silicon
C)sulfur
D)oxygen
E)iron

Accepted Answer

The electron configuration given matches with that of silicon, which is 1s2 2s2 2p6 3s2 3p2.

Question 9

What is the element with the electron configuration 
A)Cl
B)S
C)F
D)Ar
E)Be

Accepted Answer

The answer of What is the element with the electron...

Question 10

The number of electron levels in a magnesium atom is
A)1.
B)2.
C)3.
D)4.
E)5.

Accepted Answer

Magnesium has an atomic number of 12, meaning it has 12 electrons. These electrons are arranged in 3 energy levels or shells (2 in the first, 8 in the second, and 2 in the third), thus the correct answer is 3 levels.

Question 11

The correct symbol for the isotope of potassium with 22 neutrons is 
A)  
B)  
C)  
D)  
E)

Accepted Answer

The answer of The correct symbol for the isotope of...

Question 12

The atomic mass of an element is equal to
A)its mass number.
B)the average mass of all of the naturally occurring isotopes of the element.
C)its atomic number.
D)one-twelfth of the mass of a carbon-12 atom.
E)a weighted average mass of all of the naturally occurring isotopes of the element.

Accepted Answer

The atomic mass of an element is a weighted average mass of all of the naturally occurring isotopes of the element. It takes into account the relative abundance and atomic mass of each isotope. Hence, option E is the correct choice.

Question 13

The electron configuration of an atom shows
A)a description of the shape of each energy level.
B)the number of isotopes possible.
C)a diagram of an atomic nucleus.
D)the number of electrons in each energy level and sublevel.
E)the maximum number of electrons each energy level can hold.

Accepted Answer

The electron configuration of an atom tells us how many electrons are in each energy level and sublevel. It does not describe the shape of energy levels, the number of isotopes, or the diagram of the atomic nucleus. While the electron configuration does provide information about the maximum number of electrons each energy level can hold, this is not its primary purpose.

Question 14

What is the electron configuration for potassium (atomic number 19)?
A) 
B) 
C) 
D) 
E)

Accepted Answer

The answer of What is the electron configuration for potassium...

Question 15

Isotopes are atoms of the same element that have
A)the same atomic numbers but different numbers of electrons.
B)the same atomic number but different numbers of neutrons.
C)the same atomic mass but different numbers of protons.
D)the same atomic numbers but different numbers of protons.
E)different atomic numbers.

Accepted Answer

Isotopes have the same number of protons, which is the atomic number, but they have different numbers of neutrons, which can result in different atomic masses. Therefore, option B is the correct answer.

Question 16

What is the element with the abbreviated electron configuration 
A)Pd
B)Kr
C)Pt
D)Xe
E)Ni

Accepted Answer

The answer of What is the element with the abbreviated...

Question 17

The maximum number of electrons that may occupy the third energy level is
A)18.
B)32.
C)8.
D)10.
E)2.

Accepted Answer

The third energy level can hold a maximum of 2n^2 electrons, where n is the energy level number. Thus, the maximum number of electrons that may occupy the third energy level is 2(3)^2 = 18.

Question 18

What is the correct electron configuration for the lithium atom?
A) 
B) 
C) 
D) 
E)

Accepted Answer

The answer of What is the correct electron configuration for...

Question 19

Silicon has three naturally occurring isotopes: Si-28 (mass 28.0 amu); Si-29 (mass = 29.0 amu)and Si-30 (mass = 30.0 amu). If the average atomic mass of silicon is 28.1 amu, which isotope is the most abundant?
A)Si-29
B)Si-28
C)Si-30
D)All isotopes have the same natural abundance.

Accepted Answer

The average atomic mass of silicon being closer to Si-28 (the lightest isotope) indicates that it is the most abundant isotope.

Question 20

Which of the following is NOT true for the atoms ¹³N, ¹⁴N, and ¹⁵N? A) They all have the same mass number. B) They all have 7 protons. C) They all have 7 electrons. D) They are isotopes. E) They all have the same atomic number.

Accepted Answer

The atoms have different mass numbers as indicated by the numbers 113, 114, and 115 in their symbols, which represent the mass numbers.

Quiz 4: Atoms and Elements

Which of the following electron configurations is impossible?

Given the following: Which are isotopes of each other?

Chlorine has two naturally occurring isotopes. The isotope Cl-35 (mass = 35.0 amu) makes up 75.8% of the sample, and the isotope Cl-37 (mass = 37.0 amu) makes up 24.2% of the sample. What is the average atomic Mass for chlorine?

The number of electrons in the outer energy level of a neutral atom of boron (atomic number 5) is

What is the electron configuration for aluminum?

The number of orbitals in the 4d sublevel is

What is the abbreviated electron configuration for nickel (atomic number 28) ?

What element has the electron configuration

What is the element with the electron configuration

The number of electron levels in a magnesium atom is

The correct symbol for the isotope of potassium with 22 neutrons is

The atomic mass of an element is equal to

The electron configuration of an atom shows

What is the electron configuration for potassium (atomic number 19) ?

Isotopes are atoms of the same element that have

What is the element with the abbreviated electron configuration

The maximum number of electrons that may occupy the third energy level is

What is the correct electron configuration for the lithium atom?

Silicon has three naturally occurring isotopes: Si-28 (mass 28.0 amu) ; Si-29 (mass = 29.0 amu) and Si-30 (mass = 30.0 amu) . If the average atomic mass of silicon is 28.1 amu, which isotope is the most abundant?

Which of the following is NOT true for the atoms ¹³N, ¹⁴N, and ¹⁵N?