periodicity

Question 1

how are elements arranged in the periodic table

Answer 1

by increasing atomic number

Question 2

what do elements in the same group have in common

Answer 2

they have the same number of outer electrons

Question 3

how do elements in the same group differ

Answer 3

going down a group elements have an extra electron shell

Question 4

what is the trend in elements across a period on the periodic table

Answer 4

elements add an outer electron across the periodic table, they also change from metal to non metal elements

Question 5

what are the 4 types of bonds found within the first 20 elements on the periodic table

Answer 5

metallic, covalent molecular, covalent network, monatomic

Question 6

which elements within the first 20 on the periodic table are metallic

Answer 6

lithium, beryllium, sodium, magnesium, aluminium, potassium, calcium

Question 7

which of elements within the first 20 on the periodic table are covalent molecular

Answer 7

H2, N2, O2, F2, C12, P4, S8, carbon in the form of fullerene (C60)

Question 8

which elements in the first 20 on the periodic table are covalent networks

Answer 8

boron, silicon, carbon (diamond and graphite)

Question 9

which elements within the first 20 on the periodic table are monatomic

Answer 9

helium, neon, argon

Question 10

explain what is meant by the term ‘covalent radius’

Answer 10

the measure of the size of an atom from the nucleus to the outermost electron

Question 11

describe the trend in covalent radius going down a group

Answer 11

covalent radius increases as the number of occupied shells increase

Question 12

describe the trend in covalent radius going across a period

Answer 12

covalent radius decreases across the period as the nuclear charge increases

Question 13

state what is meant by the term first ionisation energy

Answer 13

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

Question 14

state what is meant by the term second ionisation energy

Answer 14

the energy required to remove the 2nd mole of electrons from one mole of gaseous atoms

Question 15

write the equation for the first ionisation energy of magnesium

Answer 15

Mg—> Mg+ + e-

Question 16

write the equation for the second ionisation energy for calcium

Answer 16

Ca+—> Ca2+ + e-

Question 17

write the equation for the third ionisation energy for aluminium

Answer 17

Al2+—> Al3+ + e-

Question 18

describe the trend in ionisation energy across a period

Answer 18

in general, across a period ionisation energy increases as nuclear charge increases

Question 19

describe the trend in ionisation energy going down a group

Answer 19

down a group ionisation energy decreases as screening/shielding increases and as the outer electrons become further away from the nuclear charge

Question 20

explain fully why the 4th ionisation for aluminium is so much higher than the 3rd ionisation energy

Answer 20

the 3rd ionisation energy is removing an electron on to form a full shell. the 4th ionisation energy is removing an electron from a full, stable shell, requiring more energy, it is also from a shell that is closer to the nuclear charge.

Question 21

state what is meant by the term electronegativity

Answer 21

electronegativity is a measure of the attraction which an atom (involved in a bond) has for shared electrons

Question 22

describe the trend in electronegativity going down a group in the periodic table

Answer 22

electronegativity decreases due to increased shielding/screening effect

Question 23

describe the trend in electronegativity across a period on the periodic table

Answer 23

electronegativity increases due to the increase in nuclear charge