Question 1

Which of the following statements best describes an element?

Accepted Answer

An element is a substance that cannot be broken down into other substances by chemical means.

Question 2

Which of the following is the fundamental unit of matter?

Accepted Answer

Atom

Question 3

What determines the atomic number of an element?

Accepted Answer

The number of protons in the nucleus

Question 4

Which of the following best explains why chemical reactions are important in biological systems?

Accepted Answer

Chemical reactions are responsible for the formation and breakdown of molecules essential for life.

Question 5

If an oxygen atom gains two electrons, what is its resulting charge?

Accepted Answer

2-

Question 6

Which of the following ions is most important for nerve impulse transmission in humans?

Accepted Answer

$$\mathrm{Na^+}$$

Question 7

What is the difference between an ionic bond and a covalent bond?

Accepted Answer

Ionic bonds involve the transfer of electrons, while covalent bonds involve the sharing of electrons.

Question 8

Which property of water allows it to dissolve many substances, making it an excellent solvent?

Accepted Answer

Its polarity

Question 9

A radioactive isotope of carbon, $$^{14}\mathrm{C}$$, is used in biological research. What makes $$^{14}\mathrm{C}$$ radioactive?

Accepted Answer

It has an unstable nucleus due to extra neutrons.

Question 10

Which of the following best describes the role of electrons in chemical bonding?

Accepted Answer

Electrons in the outermost shell (valence electrons) are involved in chemical bonding.

Question 11

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 12

Which of the following is a real-world application of radioactive isotopes in medicine?

Accepted Answer

Radioactive isotopes are used as biological tracers to track metabolic processes.

Question 13

Which of the following best explains why water has a high specific heat?

Accepted Answer

Hydrogen bonds between water molecules require more energy to break.

Question 14

Which of the following is NOT one of the four elements that make up the bulk of living cells?

Accepted Answer

Calcium

Question 15

A sodium atom ($$\mathrm{Na}) $$loses one electron to become a sodium ion. What is the charge of the resulting ion?

Accepted Answer

$$1+$$

Question 16

Which of the following best describes the relationship between protons, neutrons, and electrons in an atom?

Accepted Answer

Protons and neutrons are found in the nucleus, while electrons orbit around the nucleus.

Question 17

Which of the following best explains why ions are important in biological systems?

Accepted Answer

Ions help regulate physiological functions such as nerve impulses and muscle contraction.

Question 18

Which of the following best describes the concept of valence electrons?

Accepted Answer

Valence electrons are the electrons in the outermost shell and are involved in chemical bonding.

Question 19

Which of the following properties of water is most important for the transport of nutrients in plants?

Accepted Answer

Water's cohesion due to hydrogen bonding

The Chemical Foundations of Life: Atoms, Elements, and Water in Biology

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