Question 1

Which of the following statements best describes isotopes?

Accepted Answer

Isotopes are elements with the same number of protons but different numbers of neutrons.

Question 2

Given the isotope notation $$\$$displaystyle ^{43}$$_{20}\mathrm{Ca}$$, how many neutrons does this isotope have?

Accepted Answer

$$23$$

Question 3

Which equation correctly relates the mass number $$(A)$$, atomic number $$(Z)$$, and number of neutrons $$(n) in an $$atom?

Accepted Answer

$$A = Z + n$$

Question 4

A neutral atom of $$^{87}_{38}\mathrm{Sr}$$ has how many electrons?

Accepted Answer

$$38$$

Question 5

Which of the following is the correct isotope notation for an atom with $$15$$ protons, $$16$$ neutrons, and $$15$$ electrons?

Accepted Answer

$$^{31}_{15}\mathrm{P}$$

Question 6

If an atom has $$27$$ protons, $$32$$ neutrons, and $$27$$ electrons, what is its mass number?

Accepted Answer

$$59$$

Question 7

Which subatomic particle determines the chemical identity of an element?

Accepted Answer

Proton

Question 8

A neutral atom of $$^{75}_{33}\mathrm{As}$$ has how many neutrons?

Accepted Answer

$$42$$

Question 9

Which of the following best explains why isotopes of the same element have nearly identical chemical properties?

Accepted Answer

They have the same number of electrons and protons.

Question 10

A neutral atom of $$^{27}_{13}\mathrm{Al}$$ has how many electrons?

Accepted Answer

$$13$$

Question 11

Which of the following is true for a neutral atom?

Accepted Answer

Number of protons equals number of electrons.

Question 12

If an atom has an atomic number of $$54$$ and a mass number of $$131$$, how many neutrons does it have?

Accepted Answer

$$77$$

Question 13

Which of the following is the correct set of subatomic particles for $$^{87}_{38}\mathrm{Sr}$$?

Accepted Answer

$$38$$ protons, $$49$$ neutrons, $$38$$ electrons

Question 14

Which of the following would be the isotope notation for an atom with $$54$$ protons, $$77$$ neutrons, and $$54$$ electrons?

Accepted Answer

$$^{131}_{54}\mathrm{Xe}$$

Question 15

A hospital uses a radioactive isotope of strontium, $$^{87}_{38}\mathrm{Sr}$$, for medical imaging. How many neutrons does this isotope have?

Accepted Answer

$$49$$

Question 16

Which of the following is the correct calculation for the number of neutrons in $$^{27}_{13}\mathrm{Al}$$?

Accepted Answer

$$27 - 13 = 14$$

Question 17

Which of the following best describes the relationship between atomic number and element identity?

Accepted Answer

The atomic number uniquely identifies the element.

Question 18

A neutral atom of $$^{75}_{33}\mathrm{As} is $$used in a laboratory experiment. How many electrons does it have?

Accepted Answer

$$33$$

Question 19

Which of the following is the correct set of subatomic particles for $$^{59}_{27}\mathrm{Co}$$?

Accepted Answer

$$27$$ protons, $$32$$ neutrons, $$27$$ electrons

Isotopes and Atomic Structure: Subatomic Particles and Atomic Notation

Study Guide - Practice Questions