Ionisation energy

Question 1

Ionisation

Answer 1

the process by which an electron is removed from an atom or a molecule

Question 2

is ionisation endothermic or exothermic

Answer 2

endothermic

Question 3

why is ionisation endothermic

Answer 3

Energy is required to break the force of attraction between the electron and the central positive nucleus

Question 4

first ionisation energy

Answer 4

the energy needed to remove 1 electron from each atom of an element in 1 mol of gaseous atoms, to form 1 mol of gaseous ions with a 1 + charge

Question 5

second ionisation energy

Answer 5

energy needed to remove 1 electron from each ion of an element in 1 mol of gaseous +1 ion to form 1 mol of gaseous with a 2+ charge

Question 6

second ionisation energy equation

Answer 6

x+ (g)= x2+ + electron

Question 7

successive ionisation energy

Answer 7

the energy each time you remove an electron

Question 8

shielding effect

Answer 8

the effect of inner electrons which reduces the pull of the nucleus on the electrons in the outer shell

Question 9

nuclear charge

Answer 9

measure of how positive the nucleus is (number of protons)

Question 10

effective nuclear charge

Answer 10

net positive charge experienced by outermost electron from the nucleus- it takes into account the repulsion from inner electrons

Question 11

factors affecting ionisation energy

Answer 11

atomic radius
nuclear charge
shielding

Question 12

how does atomic radius affect ionisation energy

Answer 12

• higher the radius, lower the ionisation energy
• outermost electrons are further away from the nucleus so the pull is less

Question 13

how does nuclear charge affect ionisation energy

Answer 13

• higher the nuclear charge, higher the ionisation energy
• greaer the positive charge of nucleus, the stronger attraction of the outer electrons

Question 14

how does shielding affect ionisation energy

Answer 14

• the more inner shells, the lower the ionisation energy
• less repulsion of outer electrons so less pull towards the nucleus

Question 15

trends of successive ionisation energy

Answer 15

• increases between shells
• increases within each shell

Question 16

why does successive ionisation energy increase between shells

Answer 16

the second electron is being removed from a shell much closer to the nucleus, so the attraction is stronger

Question 17

why does succesive ionisation energy increase within the shells

Answer 17

ionisation energy increases because you are removing an electron from an increasingly positive ion.

Question 18

nuclear charge across period

Answer 18

increases
- atomic number increases