AP Biology Review Water

Can the atomic mass of an element vary?

• No, it's fixed; otherwise a new element will be formed.

• Yes. Adding or losing electrons will substantially change the atomic mass.

• Yes. Adding or losing protons will change the atomic mass without forming a different element.

• Yes. Adding or losing neutrons will change the atomic mass without forming a different element.

Tags

NGSS.HS-PS1-8

When are atoms most stable?

• when they have the fewest possible valence electrons

• when they have the maximum number of unpaired electrons

• when all the electron orbitals in the valence shell are filled

• when all the electrons are paired

Tags

NGSS.HS-PS1-1

Water molecules can form hydrogen bonds with _____.

• oils

• compounds that have polar covalent bonds

• oxygen gas (0₂) molecules

• chloride ions

Cohesion, surface tension and adhesion are the properties of water molecules that ____

• increase when temperature increases

• increase when pH increases

• are a result of hydrogen bonding

• are a result of covalent bonding

Low humidity in the atmosphere on a hot day _____

• helps in cooling because skin absorbs water from the atmosphere

• does not help in cooling because water evaporates from skin faster

• helps in cooling because water evaporates from the skin faster

• does not help in cooling because skin absorbs water from the atmosphere

Tags

NGSS.MS-ESS2-5

Why does ice float in water?

• The high surface tension of liquid water keeps the ice on top.

• The ionic bonds between the molecules in ice prevent the ice from sinking.

• Stable hydrogen bonds keep water molecules of ice farther apart than water molecules of liquid water.

• The crystalline lattice of ice causes it to be denser than liquid water.

the molar mass of glucose is 180 grams per mole (g/mol). Which of the following procedures should you carry out to make a 1 M solution of glucose? In 0.8 liter (L) of water dissolve ________.

• 1 g of glucose, and then add more water until the total volume of the solution is 1 L.

• 18 g of glucose, and then add more water until the total volume of the solution is 1 L.

• 180 g of glucose, and then add 0.2 L more of water

• 180 g of glucose, and then add more water until the total volume of the solution is 1 L.

Based on your knowledge of the polarity of water molecules, the solute molecule depicted is most likely _____.

• positively charged

• negatively charged

• without charge

• nonpolar

Tags

NGSS.HS-PS1-5

A solution with a pH of 2 has how many more protons in it than a solution with a pH of 4?

• 5x more

• 10x more

• 100x more

• 1000x more

Which of the following is considered to be a strong base (alkali)?

• HCl ---> H⁺ + Cl^-

• NH₃ + H⁺ <--> NH₄⁺

• H₂CO₃ <---> HCO₃^_ + H⁺

• NaOH ----> Na⁺ + OH^-