chapter 2 unit 1

Question 1

name the essential elements

Answer 1

Oxygen , Carbon , Hydrogen , Nitrogen , Calcium , Phosphate , Potassium , Sulfur

Question 2

The atomic number on a period table is …

Answer 2

the number of protons

Question 3

The mass number is …

Answer 3

The number of protons and neutrons

Question 4

The number of neutrons is …

Answer 4

Mass number - atomic number

Question 5

Nonpolar covalent bond

Answer 5

the electron pair is shared equally between two atoms
ex . H2

Question 6

Polar covalent bond

Answer 6

an atom is bonded to a more electronegative atom
ex . water

Question 7

non covalent

Answer 7

does not involve the sharing of electrons but rather the variations of electromagnetic interactions between molecules

Question 8

polar molecule

Answer 8

charge is unevenly distributed

Question 9

non polar

Answer 9

charge is evenly distributed

Question 10

cohesion

Answer 10

water being held together by hydrogen bonds

Question 11

adhesion

Answer 11

counteracts the downward pull of gravity (stick together)

Question 12

specific heat

Answer 12

amount of heat that must be absorbed or lost for 1 gram of water to change its temperature by 1 degree Celsius.

Question 13

heat of vaporization

Answer 13

quantity of heat a liquid
must absorb for 1g to be converted to the
gaseous state.

Question 14

Acids

Answer 14

• increases [H+] of a solution
• removes OH because it tends to combine with H+ to form H20

Question 15

Bases

Answer 15

• reduces the [H+]
• may increase OH

Question 16

Buffers

Answer 16

Are combinations of H+ donor and H+ acceptor
forms in a solution of weak acids or bases.

Work by accepting H+ ions from solution when they
are in excess and by donating H+ ions to the
solution when they have been depleted.

Buffers within a cell maintain a stable pH by
accepting excess H+ or donating H+ when H+
concentration decreases.