AS 1 Definitions

Question 0

Atomic number

Answer 0

Number of protons in the nucleus of an atom

Question 1

Mass number

Answer 1

Sum of the protons and neutrons in the nucleus of an atom

Question 2

RAM

Answer 2

Weighted mean mass of an atom of an element compared with 1/12th of the mass of an atom of carbon 12

Question 3

Relative isotopic mass

Answer 3

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

Question 4

Mole

Answer 4

Amount of substance that has the same number of particles as there are carbon atoms in 12g of carbon 12

Question 5

Empirical formula

Answer 5

Simplest whole number ratio of atoms of each element present in a compound

Question 6

Molecular formula

Answer 6

Actual number of atoms of each element present in a molecule

Question 7

Concentration

Answer 7

Amount of solute, in moles, dissolved per dm3 of solution

Question 8

Oxidation numbers

Answer 8

Numerical values associated with the atoms of each element in a compound

Question 9

Ionisation energy

Answer 9

Energy required to remove one electron from each atom in one mole of gaseous atoms to form one mole of gaseous 1+ ions

Question 10

Orbital

Answer 10

Region of space which can hold up to two electrons with opposite spins

Question 11

Ionic bonding

Answer 11

Oppositely charged ions which are bonded together by electrostatic attraction

Question 12

Covalent bonding

Answer 12

Bond formed by a shared pair of electrons

Question 13

Dative covalent bonding

Answer 13

Covalent bond in which one of the atoms provides both electrons being shared

Question 14

Electronegativity

Answer 14

Ability of an atom to attract the bonding electrons in a covalent bond

Question 15

Metallic bonding

Answer 15

Electrostatic force of attraction between a lattice of positive metal ions and delocalised electrons

Question 16

Periodicity

Answer 16

Repeating pattern of trends across different periods