Question 1

Which of the following correctly lists the three main subatomic particles of an atom and their respective charges?

Accepted Answer

Proton (positive), Neutron (neutral), Electron (negative)

Question 2

How many electrons can fill a single $$2s$$ orbital?

Accepted Answer

$$2$$

Question 3

A sodium atom ($$Na) $$has an atomic number of $$11. $$How many electrons are present in its valence shell?

Accepted Answer

$$1$$

Question 4

Which of the following elements is the most electronegative?

Accepted Answer

Sulfur ($$S)$$

Question 5

Which of the following elements is the least electronegative?

Accepted Answer

Phosphorous ($$P)$$

Question 6

What type of bond is formed when one atom donates an electron to another atom, resulting in oppositely charged ions that attract each other?

Accepted Answer

Ionic bond

Question 7

Which of the following bonds is generally considered the strongest in biological systems?

Accepted Answer

Covalent bond

Question 8

Water molecules are held together by which type of bond within the molecule, and which type of bond between molecules?

Accepted Answer

Polar covalent within, hydrogen between

Question 9

Why does ice float on water?

Accepted Answer

Ice is less dense than liquid water because hydrogen bonds create an open lattice structure

Question 10

Which property of water allows insects to walk on its surface?

Accepted Answer

Cohesion

Question 11

A solution has a pH of $$3. Is it $$acidic or basic, and does it have more $$[H^+] or$$ $$[OH^-]$$ ions?

Accepted Answer

Acidic; more $$[H^+]$$ ions

Question 12

Which of the following best describes the difference between cohesion and adhesion?

Accepted Answer

Cohesion is attraction between the same substance; adhesion is attraction between different substances

Question 13

If the pH of a solution changes from $$6 to$$ $$4$$, by what factor does the concentration of $$[H^+]$$ ions increase?

Accepted Answer

$$100$$ times

Question 14

Which of the following is true about electrons in a covalent bond?

Accepted Answer

Electrons are shared between atoms

Question 15

A molecule of $$CO_2 ($$carbon dioxide) is best described as having which type of covalent bond?

Accepted Answer

Non-polar covalent

Question 16

Which scenario best illustrates the concept of partial charge in a water molecule?

Accepted Answer

Oxygen atom has a slight negative charge, hydrogen atoms have slight positive charges

Question 17

Which of the following best explains why salt ($$NaCl) $$dissolves easily in water?

Accepted Answer

Water's partial charges attract the positive $$Na^+$$ and negative $$Cl^-$$ ions

Question 18

Which of the following is a real-world example of adhesion?

Accepted Answer

Water droplets sticking to a spider web

Question 19

Which statement about hydrogen bonds is correct?

Accepted Answer

Hydrogen bonds occur between molecules with partial charges

Question 20

A patient’s blood pH drops from $$7.4 to$$ $$7.0. $$What does this indicate about the concentration of $$[H^+]$$ ions?

Accepted Answer

The concentration of $$[H^+]$$ ions has increased by approximately $$2.5$$ times

Atoms, Chemical Bonds, and Water: Review Notes (Chapters 1-3)

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