$$\text{Number of neutrons} = \text{mass number} - \text{atomic number}$$

Question 1

Which of the following best describes the difference between an element and a compound, as illustrated in the provided diagrams?

Accepted Answer

Elements consist of only one type of atom, while compounds consist of two or more types of atoms chemically bonded together.

Question 2

Which of the following mineral elements is required in the greatest quantity by living organisms, according to the provided tables?

Accepted Answer

Calcium (Ca)

Question 3

A neutral atom of sodium ($$^{23}_{11}\mathrm{Na}) $$has how many protons, neutrons, and electrons?

Accepted Answer

11 protons, 12 neutrons, 11 electrons

Question 4

Which statement best explains why carbon-14 ($$^{14}_{6}\mathrm{C}) is $$radioactive while carbon-12 ($$^{12}_{6}\mathrm{C}) is $$stable?

Accepted Answer

Carbon-14 has an unstable ratio of neutrons to protons, causing it to decay.

Question 5

Which of the following best describes the charge and location of a neutron in an atom?

Accepted Answer

No charge, located in the nucleus

Question 6

If an atom absorbs energy and an electron moves from the first shell to the third shell, what happens to the potential energy of the electron?

Accepted Answer

The potential energy increases.

Question 7

Which of the following elements is most likely to be chemically unreactive based on its electron shell diagram?

Accepted Answer

Neon (Ne)

Question 8

A PET scan uses radioactive isotopes as tracers. Which property of these isotopes makes them useful for this purpose?

Accepted Answer

They emit energy that can be detected by imaging equipment.

Question 9

Which of the following equations correctly calculates the number of neutrons in an atom?

Accepted Answer

$$	ext{Number of neutrons} = 	ext{mass number} - 	ext{atomic number}$$

Question 10

Which of the following best explains why elements in the same group (column) of the periodic table have similar chemical properties?

Accepted Answer

They have the same number of electrons in their outermost shell.

Question 11

Which of the following is a trace element required by living organisms, as shown in the provided tables?

Accepted Answer

Iron (Fe)

Question 12

A beryllium atom has an atomic number of 4 and a mass number of 9. How many neutrons does it have?

Accepted Answer

5

Question 13

Which of the following statements about electrons is TRUE?

Accepted Answer

Electrons have negligible mass and are found in orbitals around the nucleus.

Question 14

Which of the following best describes the Octet Rule?

Accepted Answer

Atoms are most stable when their outermost shell contains 8 electrons.

Question 15

Which of the following best explains why hydrogen is an exception to the Octet Rule?

Accepted Answer

Hydrogen only needs 2 electrons to fill its outermost shell.

Question 16

Which of the following best describes the difference between a mineral element and a trace element?

Accepted Answer

Mineral elements are required in larger quantities than trace elements.

Question 17

Which of the following statements about isotopes is correct?

Accepted Answer

Isotopes of an element have the same number of protons but different numbers of neutrons.

Question 18

Which of the following best describes the energy change when an electron moves from a higher energy shell to a lower energy shell?

Accepted Answer

Energy is lost (released).

Question 19

Which of the following best explains why elements with incomplete valence shells are chemically reactive?

Accepted Answer

They tend to gain, lose, or share electrons to achieve a full outer shell.

Question 20

Which of the following is the correct nuclear notation for a beryllium atom with 4 protons and a mass number of 9?

Accepted Answer

$$^{9}_{4}\mathrm{Be}$$

Chemical Foundations of Biological Systems: Elements, Atoms, and the Periodic Table

Study Guide - Practice Questions