physics P2

Question 1

ionisation energy

Answer 1

the energy neede per mole to remove an electron from an atom in the gaseous phase

Question 2

electron affinity

Answer 2

the amount of energy released per mole when an atom or molecule gains an electron to form a negative ion

Question 3

difference between ionisation E and electron affinity

Answer 3

ionisation energy is energy required whereas electron affinity is energy released therefore the former is a positive number and the latter is negative

Question 4

electronegativity

Answer 4

the tendency of an atom to attract a shared pair of electrons to itself

Question 5

ion

Answer 5

a charged particle

Question 6

atomic radius

Answer 6

the measure of the size of an atom

Question 7

ionic radius

Answer 7

the measure of the size of an anion or cation

Question 8

chemical bond

Answer 8

a lasting attraction between atoms or ions that results in the formation of chemical compounds

Question 9

covalent bond

Answer 9

electrosttic interaction that involves the sharing of electron pairs between atoms to form molecules

Question 10

molecule

Answer 10

a neutral group of atoms bonded together which can act as a single unit in chemical reaction

Question 11

ionic bond

Answer 11

Involves the transfer of electrons to form cations and anions which form a 3D lattice structure

Question 12

metallic bond

Answer 12

an electrostatic attratction between the positively charged atomic nuclei of metal atoms and delocalised valence electrons in the metal

Question 13

mole

Answer 13

the amount of substance containing thr same number of particles as there are atoms in 12 grams of carbon-12

Question 14

molar mass

Answer 14

the mass of one mole of a substance (g/mol)

Question 15

empirical formula

Answer 15

the simplest whole number ratio of atoms in a compound

Question 16

dispersion

Answer 16

process whereby the particles of one substance are scattered throughout another substance

Question 17

solution

Answer 17

homogenous mixture of two or more substances

Question 18

saturated solution

Answer 18

solubility limit has been reached and no ore solute can be dissolved

Question 19

physical change

Answer 19

affects the form of a chemical substance but not its chemical composition

Question 20

dissociation

Answer 20

a general process whereby ionic compounds seperate into ions, usually in a revesable manner

Question 21

hydration

Answer 21

process where ions become surrounded with water molecules

Question 22

ionisation

Answer 22

molecules react with water to form ions in solution

Question 23

electrolyte

Answer 23

a substance that contains free ions and behaves as an electrically conductive medium

Question 24

precipitate

Answer 24

solid that forms in a solution during a chemical reaction

Question 25

ion exchange reaction

Answer 25

reaction where positive ions exchange their respective negative ions due to a driving force

Question 26

relative atomic mass

Answer 26

mass of a particle on a scale where an atom of carbon 12 has a mass of 12 units

Question 27

aufbau pinciple (bottom up)

Answer 27

electrons fill atomic orbitals of the lowest available enrgy levels first (bottom up)

Question 28

Hund's rule (singly before doubly)

Answer 28

every orbital in an energy level is singly occupied with an electron before it is doubly occupied and all electrons in a singly occupied orbital have the same spin

Question 29

pauli's exclusion principle (max of 2)

Answer 29

orbitals can accommodate a maximum of 2 e- provided hey spin in opposite directions

Question 30

pure substance

Answer 30

substance containing only one kind of particle

Question 31

aqueous solution

Answer 31

a solution where water is the solvent

Question 32

valency

Answer 32

the number of chemical bonds an atom can form OR the number of e- that must be lost or gained in order to form a full outer energy level