Topic 2- Foundations in Chemistry

Question 1

atomic number

Answer 1

number of protons in the atom

Question 2

isotope

Answer 2

elements with the same number of protons but different number of neutrons

Question 3

relative isotopic mass

Answer 3

mass of an isotope of an element compared to 1/12 th the mass of an atom of carbon-12

Question 4

relative atomic mass

Answer 4

the weighted mean mass of an atom of an element compared to 1/12 yh the mass of an atom of carbon-12

Question 5

cation

Answer 5

positive ion

Question 6

anion

Answer 6

negative ion

Question 7

amount of substance

Answer 7

number of particles in a substance

Question 8

molecular formula

Answer 8

number of atoms of each element in a molecule

Question 9

empirical formula

Answer 9

simplest whole-number ratio of atoms of each element in a compound

Question 10

relative molecular mass

Answer 10

the weighted mean mass of a molecule of a compound compared with 1/12th the mass of an atom of carbon-12

Question 11

relative formula mass

Answer 11

the weighted mean mass of the formula unit of a compound compared with 1/12th the mass of an atom of carbon-12

Question 12

hydrated

Answer 12

a crystalline compound containing water molecules

Question 13

water of crystallation

Answer 13

water molecules that are bonded into a crystalline structure of a compound

Question 14

anhydrous

Answer 14

containing no water molecules

Question 15

standard solution

Answer 15

a solution of a known concentration

Question 16

molar gas volume

Answer 16

the volume per mole of gas molecules at a stated temperature and pressure

Question 17

limiting reagent

Answer 17

the reactant which is not in excess, which will be used up first and stop the reaction

Question 18

atom economy

Answer 18

measure of efficiency of a chemical reaction

Question 19

strong acid

Answer 19

an acid that dissociates completely in a solution

Question 20

weak acid

Answer 20

an acid that dissociates only partially in a solution

Question 21

alkali

Answer 21

a type of base that dissolves in water forming hydroxide ions

Question 22

neutralisation

Answer 22

a chemical reaction in which an acid and a base react together to form a salt

Question 23

redox reaction

Answer 23

a reaction involving reduction and oxidation

Question 24

orbital

Answer 24

region around the nucleus that can hold up to two electrons with opposite spins

Question 25

s-block

Answer 25

highest energy electron in the s subshell

Question 26

p-block

Answer 26

highest energy electron in the p subshell

Question 27

d-block

Answer 27

highest energy electron in the d subshell

Question 28

ionic bonding

Answer 28

electrostatic attraction between oppositely charged ions

Question 29

covalent bonding

Answer 29

electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atom

Question 30

dative covalent bond

Answer 30

a shared pair of electrons in which the bonded pair has been provided by one of the bonding atoms only

Question 31

tetrahedral

Answer 31

4 bond pairs and 0 lone pairs with a bond angle of 109.5

Question 32

pyramidal

Answer 32

3 bond pairs and 1 lone pair with a bond angle of 107

Question 33

non-linear

Answer 33

2 bond pairs and 2 lone pairs with a bond angle of 104.5

Question 34

linear

Answer 34

2 bond pairs and 0 lone pairs with a bond angle of 180

Question 35

trigonal planar

Answer 35

3 bond pairs and 0 lone pairs with a bond angle of 120

Question 36

octahedral

Answer 36

6 bond pairs and 0 lone pairs with a bond angle of 90

Question 37

electronegativity

Answer 37

a measure of the attraction of a bonded atom for the pair of electrons in a covalent bond

Question 38

non-polar bond

Answer 38

no charge separation across a bond or in a molecule

Question 39

polar bond

Answer 39

bonded electron pair shared unequally between the bonded atoms

Question 40

intermolecular forces

Answer 40

an attractive force between molecules

Question 41

London forces

Answer 41

temporary attractive force that results when the electrons in two adjacent atoms occupy positions that make the atoms form temporary dipoles

Question 42

permanent dipole

Answer 42

a small charge difference that does not change across a bond, with partial charges on the bonded atoms

Question 43

hydrogen bond

Answer 43

a strong dipole-dipole attraction between an electron-deficient hydrogen atom of -NH,-OH or HF on one molecule and a lone pair of electrons on a highly electronegative atom

Question 44

oxidation state

Answer 44

the oxidation number