Question 1

Which of the following best describes a trace element?

Accepted Answer

An element that is essential to life but required in extremely small amounts.

Question 2

A compound differs from an element in that:

Accepted Answer

A compound has characteristics different from those of its elements.

Question 3

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 4

If an atom has an atomic number of 8 and a mass number of 18, how many neutrons does it have?

Accepted Answer

$18 - 8 = 10$

Question 5

Which of the following is NOT a correct statement about matter?

Accepted Answer

Matter is found only in the solid state.

Question 6

A patient is diagnosed with an iodine deficiency. Which of the following best explains the biological significance of this trace element?

Accepted Answer

Iodine is required in small amounts for proper thyroid function.

Question 7

Which of the following best describes an atom?

Accepted Answer

The smallest unit of matter that still retains the properties of an element.

Question 8

A neutral atom of sodium has an atomic number of 11. How many electrons does it have?

Accepted Answer

$11$

Question 9

Which of the following is a real-world example of the importance of trace elements in public health?

Accepted Answer

Adding iodine to table salt to prevent thyroid disorders.

Question 10

Which of the following best explains why most compounds contain at least three or four elements?

Accepted Answer

Complex biological functions require the interaction of multiple elements.

Question 11

Which of the following is true about protons, neutrons, and electrons?

Accepted Answer

Protons have a positive charge, neutrons have no charge, and electrons have a negative charge.

Question 12

Which of the following would be considered a compound?

Accepted Answer

Water ($H_2O$)

Question 13

If a radioactive isotope of carbon has 6 protons and 8 neutrons, what is its mass number?

Accepted Answer

$6 + 8 = 14$

Question 14

Which of the following is a correct statement about elements and compounds?

Accepted Answer

An element is a substance consisting of only one type of atom, while a compound contains two or more different elements combined in a fixed ratio.

Question 15

Which of the following best explains why trace elements are sometimes difficult to fulfill in the human diet?

Accepted Answer

They are required in very small amounts and may not be present in sufficient quantities in common foods.

Question 16

A scientist discovers a new atom with 15 protons, 16 neutrons, and 15 electrons. What is the atomic number and mass number of this atom?

Accepted Answer

Atomic number: $15$, Mass number: $15 + 16 = 31$

Question 17

Which of the following is a property of a radioactive isotope?

Accepted Answer

Its nucleus decays, giving off particles and energy.

Question 18

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

Accepted Answer

The atomic number is the number of protons in an atom and determines the element's identity.

Question 19

Which of the following is a real-life consequence of not getting enough trace elements in the diet?

Accepted Answer

Increased risk of diseases such as anemia or goiter.

Question 20

Which of the following best explains why elements are considered the building blocks of matter?

Accepted Answer

Elements are pure substances that cannot be broken down into simpler substances by chemical means.

General Biology Study Notes: Matter, Elements, and Atoms

Study Guide - Practice Questions