(a)(i) Isotopy
(ii) They have different mass numbers or number of neutrons.
(iii) —Hydrogen, —Chlorine. —Carbon, —Oxygen.
(iv) 1 S2S2P3S3P
(b)(i) 1. DIFFERENCES IN PHYSICAL PROPERTIES
METALS | NON — METALS |
Good conductors of heat and electricity | Poor conductors of heat and electricity |
Malleable - can be beaten into thin sheets | Not malleable / brittle |
Ductile — can be stretched into wire | Non ductile / biittle |
Possess metallic luster | Do not possess metallic luster |
Are sonorous | Not sonorous |
Solid at room temperature except mercury / high melting point | Solids, liquids or gases at room temperature / low melting point |
2. DIFFERENCES IN CHEMICAL PROPERTIES
METALS NON | METALS |
Lose their valence electrons easily / ionize by electron loss | Gain or share valence electrons easily / ionize by electron gain |
Form oxides that are basic / amphoteric | Form oxides that are acidic / neutral |
Are good reducing agents | Are good oxidizing agents |
Have lower electro negativities | Have higher electro negativities |
Have low ionization energy | Have high ionization energy |
(Some reactive metals) react with dilute acids to give off hydrogen | Do not react with dilute acids to give off hydrogen. |
(ii) (l) BeO, AlO, ZnO, SnO, PbO, PbO
(II) LiH, NaH, KH, CaCO MgH
(III) LiCO, BeCO, MgCO, CaCO, ZnCO, PbCO
(IV) AlCl, MgCl, PCl, SiCl, NHCl
(c)(i) - form coloured compounds / ions, - exhibit variable oxidation states. - form complex compounds / ion. - have magnetic properties (paramagnetism). - have catalytic properties.
(ii) —> 1s2s2p3s3p3d4s are fully filled
(d) Mr(MgCO) = 24 + 12 + (16 x 3) 84
Mr(NaCO) = (23 x 2) +12 + (3 x 16) = 106
moles of MgCO = = 0.04
moles of NaCO = moles of MgCO = 0.04
mass of NaCO = 0.04 x106 = 4.24g
OR
Mr(MgCO) = 24 + 12 + (1 6 x 3) 84
Mr(NaCO) = (23 x 2) +12 + (3 x 16) = 106
84g of MgCO produced from 10g NaCO
3.36g of MgCO will be produced
From 106 x = 4.24g