topic 1: Periodicity in Elements 1-20

Question 1

define atomic number

Answer 1

number of protons

Question 2

define periodicity

Answer 2

trends of recurring variations in element properties with increasing atomic number

Question 3

define covalent radius

Answer 3

the distance between the nuclei of 2 bonded atoms

Question 4

define first ionisation energy

Answer 4

the energy required to remove 1 mole of electrons from 1 mole of gaseous atoms

Question 5

which 3 factors affect the ionistion energy

Answer 5

-atomic size
-nuclear charge
-the shielding effect of inner shells

Question 6

define electronegativity

Answer 6

the tendency of an atom to attract a bonding pair on electrons