Lecture 2: Basic Chem & water

Question 1

valence electrons

Answer 1

outer electrons in a shell

Question 2

valence shell

Answer 2

outermost electron shell

Question 3

covalent bonds

Answer 3

sharing of a pair of valence electrons

Question 4

electronegativity

Answer 4

the attractive force that an atomic nucleus exerts on electrons in a chemical bond

Question 5

which of 6 main elements has highest electronegativity?

Answer 5

Oxygen

Question 6

non-polar covalent bond

Answer 6

covalent bond between two atoms of the same element

electronegativity

Question 7

polar covalent bond

Answer 7

when an atom is bonded with another atom with higher electronegativity
.5

Question 8

ions

Answer 8

oppositely charged atoms

Question 9

cation

Answer 9

positively charged ion

Question 10

anion

Answer 10

negatively charged ion

Question 11

ionic bond

Answer 11

attraction between cation and anion

Question 12

ionic compounds (salts)

Answer 12

compounds formed by ionic bonds

Question 13

hydrogen bond

Answer 13

a weak attraction between a partial positive H atom and partial negative O or N atom

Question 14

how many hydrogen bonds are in a single molecule of water?

Answer 14

none

Question 15

where do hydrogen bonds form?

Answer 15

between water molecules or between partial positive H atoms and partial negative O or N atoms

Question 16

high heat capacity of water

Answer 16

water resistant to temperature change due to hydrogen bonds

Question 17

high heat vaporization of water

Answer 17

water resistant to evaporation due to hydrogen bonds

Question 18

cohesion

Answer 18

water sticks to itself due to hydrogen bonds

Question 19

adhesion

Answer 19

water sticks to other water molecules due to hydrogen bonds

Question 20

hydrophilic

Answer 20

to be attracted to water (polar molecules)

Question 21

hydrophobic

Answer 21

to repel water (non polar molecules)

Question 22

acids

Answer 22

INCREASE proportion of H+ to OH- in a solution

Question 23

bases

Answer 23

REDUCE proportion of H+ to OH- in a solution

Question 24

macromolecules

Answer 24

polymers made of monomers

Question 25

condensation (dehydration)

Answer 25

removal of water to link monomers togerther

Question 26

hydrolysis

Answer 26

addition of water to break up a polymer into monomers