periodicity

Question 1

what blocks are there, in order?

Answer 1

s block, d block ,p block (f block)

Question 2

how many electrons in each block?

Answer 2

-s block, 2 electrons
-p block, 6 electrons
-d block, 10 electrons

Question 3

what is the trend in atomic radius across period 3?

Answer 3

decreases due to nuclear charge, outer electrons are pulled closer, which makes the atomic radius smaller.

Question 4

what is the trend in melting points across period 3?

Answer 4

melting points increase from sodium so silicon, but generally decrease from silicon to argon

Question 5

describe the structure of Na, Mg and Al.

Answer 5

all metals, m.p increase as the bonds get stronger due to increasing positive charge, increasing number of delocalised electrons and decreasing radius.

Question 6

describe the structure of silicon.

Answer 6

macromolecular, strong covalent bonds, lots of energy is needed to break bonds

Question 7

describe the structure of P4, S8, Cl2 and Ar.

Answer 7

all molecular substances, the more atoms the stronger the van der waals forces. Ar has the lowest m.p as it exists as individual atoms

Question 8

what is the trend in ionisation energy?

Answer 8

general increase, due to to increasing attraction between protons and outer electrons