1. 28 Ni Nickel 200.59 Nickel is a metal that has a silver color, with a polish. It is one of the four elements that become magnetic when placed at room temperature. THE REST WAS DONE IN SCHOOL. 82 Pb Lead 207.20 5 B Boron 10.81 10 Ne Neon 20.18

2. 2 He Helium 4.00

3. Lead More reactive Reaction of lead with water The surface of metallic lead is protected by a thin layer of lead oxide, PbO. It does not react with water under normal conditions. Reaction of lead with the halogens Lead metal reacts vigorously with fluorine, F2, at room temperature and chlorine, Cl2, on warming to form the poisonous dihalides lead(II) fluoride, PbF2, and lead(II) chloride, PbCl2, respectively. Reaction of lead with acids The surface of metallic lead is protected by a thin layer of lead oxide, PbO. This renders the lead essentially insoluble in sulphuric acid, and so, in the past, a useful container of this acid. Lead reacts slowly with hydrochloric acid and nitric acid, HNO3. In the latter case, nitrogen oxides are formed together with lead(II) nitrate, Pb(NO3)2. Reaction of lead with bases Lead dissolves slowly in cold alkalis to form plumbites. Boron High reactivity Reaction of boron with air The behaviour of boron to air depends upon the crystallinity of the sample, temperature, particle size, and purity. By and large, boron does not react with air at room temperature. At higher temperatures, boron does burn to form boron (III) oxide, B2O3. Reaction of boron with water Boron does not react with water under normal conditions. Reaction of boron with the halogens Boron reacts vigorously with the halogens fluorine, F2, chlorine, Cl2, bromine, Br2 to to form the trihalides boron(III) fluoride, BF3, boron(III) chloride, BCl3, and boron(III) bromide, BBr3 respectively. Reaction of boron with acids Crystalline boron does not react with boiling hydrochloric acid, HCl, or boiling hydrofluoric acid, HF. Powdered boron oxidizes slowly when treated with concentrated nitric acid, HNO3. Neon Less reactive Reaction of neon with air Neon does not react with air, even under extreme conditions. Reaction of neon with water Neon does not react with water. It does, however, dissolve slightly to the extent of about 10.5 cm3 kg-1 at 20°C (293 K) Reaction of neon with the halogens Neon does not react with any of the halogens. Reaction of neon with acids Helium does not react with any acids. Reaction of neon with bases Neon does not react with any bases. Helium Less reactive Reaction of helium with air Helium does not react with air, even under extreme conditions. The atmosphere contains traces of helium. Reaction of helium with water Helium does not react with water. It does, however, dissolve slightly to the extent of about 8.61 cm3 kg-1 at 20°C (293 K). Reaction of helium with the halogens Helium does not react with any of the halogens. Reaction of helium with acids Helium does not react with acids. Reaction of helium with bases Helium does not react with any bases.