2

Question 1

how many atoms each of H and S would you need to produce a stable molecule (covalent bonds)

Answer 1

2H and 1S

Question 2

polarity of molecules

Answer 2

based on difference in electronegativity in atoms

Question 3

H bonds

Answer 3

electrostatic attraction between H atoms and electronegative atom

Question 4

ionic bond

Answer 4

electrostatic bond between positive and negative ions

Question 5

elements with high abundance in cells

Answer 5

C, H, O, N, P
Because they are small (fewer protons and neutrons allows them to be compact) and because they form strong covalent bonds with one another

Question 6

types of organic macromolecules

Answer 6

carbohydrates
proteins
nucleic acids
lipids

Question 7

VDW forces

Answer 7

due to the motion of electrons along long, non polar molecules
produces asymettry in electron distribution
weal electrostatic attraction

Question 8

orbital

Answer 8

region of space where an electron is present most of the time
electrons in orbitals close to nucleus have less energy

Question 9

patterns in periodic table

Answer 9

first 3 horizontal rows, elements in the same row have the same number of shells and so also have the same number and types of orbitals available to be filled by electrons
elements in a vertical column are called a group/family
members of a group all have the same number of electrons in their outermost shell

Question 10

electronegativity patterns

Answer 10

increases across the row
as number of protons increases
electrons are held more tightly to the nucleus

Question 11

polar covalent bond

Answer 11

electrons shared unequally between two atoms (difference in electronegativity)

Question 12

nonpolar covalent bond

Answer 12

atoms have the same, or similar, electronegativity so atoms share electrons almost equally

Question 13

Properties of water

Answer 13

hydrophilic interactions 
hydrophobic interaction 
highly cohesive 
solid water less dense than liquid water 
high heat capacity 
high heat of evaporation

Question 14

acidic

Answer 14

lower than 7 pH; when concentration of protons is higher than that of hydroxide ions

Question 15

basic

Answer 15

higher than 7 pH; when concentration of protons is lower than that of hydroxide ions

Question 16

acid

Answer 16

molecule that releases a proton

Question 17

base

Answer 17

molecule that accepts a proton in aqueous soluition

Question 18

lipids

Answer 18

hydrophobic

group together to function as storage compounds as they mix poorly with water

Question 19

Saturated fatty acids

Answer 19

no double bonds
lienar in shape
flat linear shape: pack tightly together, solid at room temp

Question 20

unsaturated fatty acids

Answer 20

one or more double bonds
bent and kinks into shape
bent shape: difficult to pack tightly together, liquid at room temp

Question 21

Cis double bonds

Answer 21

H on same side of C chain
bent or kinked shape
close proximity leads to extra electrostatic repulsion

Question 22

trans double bonds

Answer 22

H on opposite sides of C chain
more linear shape
arrangement greatly reduces impact on shape
not easily recognised by enzymes so harder to metabolise and break down