definitions :)

Question 1

isotopes

Answer 1

two ATOMS of the SAME ELEMENT that have DIFFERENT relative atomic masses, so each atoms has a DIFFERENT NO. of NEUTRONS

Question 2

relative isotopic mass

Answer 2

the MASS of an ATOM of an ISOTOPE compared to 1/12 of the mass of an atom of carbon-12 which has a mass of 12

Question 3

relative atomic mass (Ar)

Answer 3

the WEIGHTED AVG. MASS of an ATOM of an ELEMENT compared to 1/12 of the mass of an atom of carbon-12 which has a mass of 12

Question 4

ionisation energy (1st IE)

Answer 4

the ENERGY requires to remove ONE MOLE of ELECTRONS from ONE MOLE of atoms of the element in the GASEOUS state (to from ONE MOLE of +1 ions) (endothermic reaction)

Question 5

electronegativity

Answer 5

the ABILITY of an ATOM to ATTRACT an ELECTRON PAIR in a covalent bond

Question 6

mole

Answer 6

amount of substance that contains the same no. of particles as the no. of carbon atoms in 12g of carbon-12 ..

Question 7

theoretical yield

Answer 7

the max. possible mass of a product, so no losses in mass

Question 8

actual yield

Answer 8

the actual yield obtained in the reaction by weighing not by calculation

Question 9

Avogadro’s constant

Answer 9

6.02 times 10^23

the no. of particles in a mole

Question 10

relative molecular mass (Mr)

Answer 10

the AVG. MASS of a MOLECULE of a COMPOUND compared with 1/12 of the mass of an atom of carbon-12

Question 11

molar mass (also Mr)

Answer 11

the mass per mole of substance in g/mol

Question 12

homologous series

Answer 12

SAME FUNCTIONAL GROUP hence SAME CHEMICAL PROPERTIES and SAME GENERAL FORMULA (e.g. alkanes)

Question 13

isomers

Answer 13

molecules/compounds with SAME MOLECULAR FORMULA and DIFFERENT STRUCTURAL FORMULA

Question 14

structural isomers

Answer 14

same molecular formula but different structural formula

Question 15

stereoisomers

Answer 15

same molecular formula and same structural formula but different arrangements of atoms

Question 16

saturated hydrocarbon

Answer 16

hydrogen and carbon compounds with single c-c bonds so no more bonds can form (e.g. alkenes)

Question 17

unsaturated hydrocarbon

Answer 17

hydrogen and carbon compounds with double (or triple) c=c bonds (e.g. alkanes)

Question 18

cracking

Answer 18

process to BREAK down LONGER CHAIN FRACTIONS, which are often overproduced, to MORE USEFUL, SHORTER CHAIN FRACTIONS (that aren’t naturally present in crude oil)

Question 19

reforming

Answer 19

process to obtain more useful fractions from less useful ones, under heat and pressure branched chain hydrocarbons are formed into longer, straight chained hydrocarbons

Question 20

homolytic fission

Answer 20

breaking of covalent bonds so that one electron goes to each atom

Question 21

heterolytic fission

Answer 21

breaking of covalent bonds so that both electrons goes to the same atom

Question 22

functional group isomers

Answer 22

isomers that contain DIFFERENT functional groups hence they belong to DIFFERENT homologous series