BIO 120: CH. 2,3, and 4: Quiz 2

About 25 of the 92 natural elements are known to be essential to life. Which 4 of these 25 elements make up approximately 96% of living matter?

A.) oxygen, hydrogen, calcium, nitrogen

B.) carbon, hydrogen, nitrogen, oxygen

C.) carbon, oxygen, phosphorus, hydrogen

D.) carbon, sodium, hydrogen, nitrogen

B.) carbon, hydrogen, nitrogen, oxygen

Carbon- 14 has the same___?

A.) atomic number and atomic mass as carbon-12

B.) number of protons but more neutrons than carbon-12

C.) atomic mass as both carbon-12 and carbon- 13

D.) atomic number and thus number of neutrons as carbon-13

B.) number of protons but more neutrons than carbon-12

Bond between two atoms that are equally electronegative are___?

A.) polar covalent bonds

B.) hydrogen bonds

C.) ionic bonds

D.) nonpolar covalent bonds

D.) nonpolar covalent bonds

Which of the following correctly describes chemical equilibrium?

A.) Forward and reverse reactions continue with no net effect on the concentrations of the reactants and products

B.) Concentrations of products are higher than the concentrations of the reactants

C.) There are equal concentrations of reactants and products, and the reaction have stopped

D.) There are equal concentrations of products and reactants while forward and reverse reactions continue

A.) Forward and reverse reactions continue with no net effect on the concentrations of the reactants and products

The partial negative charge in a molecule of water occurs because___?

A.) one of the hydrogen atoms donates an electron to the oxygen atom

B.) the oxygen atom has two Paris of electrons in its valence shell that are not neutralized by hydrogen atoms

C.) the electrons shared between the oxygen and hydrogen atoms spend more time around the oxygen atom nucleus than around the hydrogen atom nucleus

D.) the oxygen atom donates an electron to each of the hydrogen atoms

C.) the electrons shared between the oxygen and hydrogen atoms spend more time around the oxygen atom nucleus than around the hydrogen atom nucleus

Water molecules can form hydrogen bonds with___?

A.) oxygen gas (O2) molecules

B.) oils

C.) chloride ions

D.) compounds that have polar covalent bonds

D.) compounds that have polar covalent bonds

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

A.) 1,000 times more

B.) 5 times more

C.) 100 times more

D.) 10 times more

C.) 100 times more

Which of the following statements is true about buffer solutions?

A.) they fluctuate in pH when either acids or bases are added to them

B.) they maintain a constant pH when acids are added to them but not when bases are added to them

C.) they maintain a relatively constant pH when either acids or bases are added to them

D.) they maintain a constant pH of 7

C.) they maintain a relatively constant pH when either acids or bases are added to them

Carbon dioxide in the atmosphere dissolves with the raindrops. The pH of raindrops is___?

A.) same as pure water

B.) slightly basic

C.) slightly acidic

D.) depends on the altitude where rain drops are formed

C.) slightly acidic

How would acidification of seawater affect marine organisms? Acidification of seawater would___?

A.) decrease dissolved carbonate concentrations and hinder growth of corals and shell-building animals

B.) increase dissolved carbonate concentrations and hinder growth of corals and shell-building animals

C.) increase dissolved carbonate concentrations and promote faster growth of corals and shell-building animals

D.) decrease dissolved carbonate concentrations and promote faster growth of corals and shell-building animals

A.) decrease dissolved carbonate concentrations and hinder growth of corals and shell-building animals