chemistry for life

Question 1

atom

Answer 1

a single particle of an element, consisting of a positively charged nucleus surrounded by a cloud of negatively charged electrons

Question 2

molecule

Answer 2

a group of two or more atoms held together by covalent bonds

Question 3

compound

Answer 3

a molecule that contains two or more elements

Question 4

intermolecular forces

Answer 4

the weaker bonds that form between molecules

Question 5

ion

Answer 5

an atom that has gained or lost an electron, giving it a negative or positive charge

Question 6

ionic bonding

Answer 6

the atoms involved in the reaction donate or receive electrons

Question 7

covalent bonding

Answer 7

the atoms involved in the reaction share electrons

Question 8

nitrate

Answer 8

anion needed in plants for the formation of amino acids and therefore proteins from the products of photosynthesis, and also for the formation of DNA

Question 9

phosphate

Answer 9

anion need in all living organism including plants and animals in the formation of ATP and ADP as well as DNA and RNA

Question 10

chloride

Answer 10

anion needed in nerve impulses and many secretory systems

Question 11

hydrogen carbonate

Answer 11

anion needed for buffering the blood to prevent it from becoming too acidic

Question 12

sodium

Answer 12

cation needed in nerve impulses and many secretory systems

Question 13

calcium

Answer 13

cation needed for the formation of calcium pectate for the middle lamella between two cell walls in plants, an for bone formation and muscle contraction in animals

Question 14

hydrogen

Answer 14

cation needed in cellular respiration and photosynthesis, and in numerous pumps and systems in organisms as well as pH balance

Question 15

magnesium

Answer 15

cation needed for production of chlorophyll in plants

Question 16

non-polar

Answer 16

when the charge in a molecule is evenly spread across it

Question 17

polar

Answer 17

when one side of a molecule has a slight positive charge and the other side has a slight negative charge

Question 18

hydrogen bond

Answer 18

a temporary bond between an oxygen on one molecule and a hydrogen on another molecule

Question 19

cohesion

Answer 19

when water molecules ‘stick’ to each other via hydrogen bonding

Question 20

adhesion

Answer 20

when water molecules ‘stick’ to a surface via hydrogen bonding

Question 21

coolant

Answer 21

a liquid or gas that is used to remove heat from something

Question 22

solute

Answer 22

a substance that dissolves in a solvent

Question 23

solution

Answer 23

where a solute is dissolved in a solvent

Question 24

solvent

Answer 24

a substance that other substances can dissolve in

Question 25

hydrophilic

Answer 25

attracted to and mixed with water

Question 26

hydrophobic

Answer 26

repels and does not mix with water

Question 27

surface tension

Answer 27

the cohesive forces between water molecules lead to a resistance

Question 28

specific heat capacity

Answer 28

the amount of energy needed to change the temperature of 1kg of the substance by 1 degrees

Question 29

latent heat of evaporation

Answer 29

volume of energy needed to change a substance from a liquid to a vapour