Question 1

Which of the following best explains why water has a high heat capacity and is able to moderate temperature changes in the human body?

Accepted Answer

Water molecules form extensive hydrogen bonds, which require significant energy to break.

Question 2

An atom of sodium (Na) has 11 protons and 11 electrons. If it loses one electron, what is the resulting charge and what type of ion does it become?

Accepted Answer

It becomes a positively charged cation.

Question 3

Which of the following is TRUE regarding the octet rule in chemical bonding?

Accepted Answer

Atoms are most stable when they have 8 electrons in their outermost shell.

Question 4

Which of the following best describes a covalent bond?

Accepted Answer

Electrons are shared between two or more nonmetal atoms.

Question 5

A molecule of oxygen ($$O_2) is $$held together by which type of bond?

Accepted Answer

Nonpolar covalent bond

Question 6

Which of the following elements is NOT one of the four major elements that make up the human body?

Accepted Answer

Calcium (Ca)

Question 7

What is the primary function of ATP in the cell?

Accepted Answer

To provide energy for cellular processes

Question 8

Which of the following best describes the difference between organic and inorganic molecules?

Accepted Answer

Organic molecules contain carbon-hydrogen bonds; inorganic molecules do not.

Question 9

If an atom has 8 protons, 8 neutrons, and 8 electrons, what is its atomic number and what element is it?

Accepted Answer

Atomic number 8; Oxygen

Question 10

Which of the following best explains why water is an excellent solvent for many biological molecules?

Accepted Answer

Water is polar and can interact with charged and polar molecules.

Question 11

Which of the following statements about hydrogen bonds is CORRECT?

Accepted Answer

Hydrogen bonds are weak attractions between partially positive and partially negative atoms in polar molecules.

Question 12

Which of the following is a trace element required by the human body?

Accepted Answer

Iron (Fe)

Question 13

A sodium atom ($$Na) $$reacts with a chlorine atom ($$Cl) to $$form sodium chloride ($$NaCl). $$What type of bond is formed and what is the process?

Accepted Answer

Ionic bond; $$Na$$ transfers an electron to $$Cl$$

Question 14

Which of the following molecules contains a polar covalent bond?

Accepted Answer

$$H_2O$$

Question 15

What is the maximum number of electrons that can be held in the second electron shell of an atom?

Accepted Answer

$$8$$

Question 16

Which property of water allows it to act as a lubricant between two adjacent surfaces in the body?

Accepted Answer

Protection and lubrication

Question 17

Which of the following best describes a free radical?

Accepted Answer

An unstable reactive molecule with unpaired electrons

Question 18

Which of the following is the correct order of bond strength from weakest to strongest?

Accepted Answer

Hydrogen bond \u003c Polar covalent bond \u003c Single covalent bond \u003c Double covalent bond \u003c Triple covalent bond

Question 19

Which of the following best explains why sweating cools the body?

Accepted Answer

Sweat absorbs heat as it evaporates, carrying heat away from the skin.

Question 20

Which of the following is TRUE about valence electrons?

Accepted Answer

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

Chapter 2: The Chemistry of Life – Study Notes for Anatomy & Physiology

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