Chemical foundations of biology (2&4)

Question 1

element

Answer 1

a substance which cannot be broken down into other substances

Question 2

Mass

Answer 2

physical quantity of a substance

Question 3

molecule

Answer 3

a group of atoms bonded together

Question 4

compound

Answer 4

containing 2 or more elements

Question 5

polar

Answer 5

molecule with a partial electric charge (doesn’t like sharing electrons)

Question 6

non-polar

Answer 6

molecule or atom with no electrical charge (likes sharing electrons)

Question 7

protons

Answer 7

positive charge, located in nucleus

Question 8

neutrons

Answer 8

no charge, located in nucleus

Question 9

electrons

Answer 9

negative charge, found in orbitals around the nucleus

Question 10

when do atoms have no charge

Answer 10

when the electrons=protons

Question 11

when do ion have a charge

Answer 11

when the electrons don’t equal the protons

Question 12

cation

Answer 12

protons > electrons = positive net charge

Question 13

anion

Answer 13

electrons > protons= negative net charge

Question 14

OIL RIG

Answer 14

oxidation is loss of electron (and energy) +

reduction is gaining an electron (and energy) -

Question 15

what kind of bonds hold the molecules of a compound together

Answer 15

chemical bonds

Question 16

Consider water (H2O) and nitrogen gas (N2); which of the following is correct?

Answer 16

• both are molecules because they’re both more than one atom

- water is a compound because it has 2 different atoms

Question 17

ionic bonds

Answer 17

• attraction of oppositely charged ions

- strongest type of bond

Question 18

covalent bonds

Answer 18

form when atoms share electrons

• number of protons = electrons
• strength depends on number of shared electrons

Question 19

nonpolar covalent bonds

Answer 19

equal sharing of electrons

Question 20

polar covalent bonds

Answer 20

unequal sharing of electrons

Question 21

what can influence chemical reactions

Answer 21

temp
concentration of substrates and products
catalysts

Question 22

what kind of bond is water

Answer 22

hydrogen bond=weak attraction between molecules

Question 23

Cohesion (properties of water)

Answer 23

water molecules stick together (surface tension)

Question 24

Adhesion (properties of water)

Answer 24

water molecules stick to other polar molecules

Question 25

high specific heat (properties of water)

Answer 25

• lots of energy to change temp

- retains heat well

Question 26

high heat of vaporization (properties of water)

Answer 26

lots of energy to turn into gas

Question 27

water is more dense than ice (properties of water)

Answer 27

increased h-bonding=increased empty space

Question 28

repels nonpolar (properties of water)

Answer 28

they are hydrophobic (water fearing)

Question 29

good solvent for polar molecules and ions (properties of water)

Answer 29

they are hydrophilic (water loving)

Question 30

can form ions (properties of water)

Answer 30

h20 -> OH- + H+

Question 31

what does low PH mean

Answer 31

lots of hydrogen

acidic

Question 32

what does high ph mean

Answer 32

little hydrogen

basic

Question 33

buffers

Answer 33

-release H+ when base is added
-absorb H+ when acid is added
=keeps h+ relatively constant

Question 34

In order to neutralize the charge on a sodium ion (Na+), it must be:

Answer 34

reduced