Name the following:

(a) Two metals which give hydrogen with cold water.

(b) A metal which liberates hydrogen only when ste am is passed over red hot metal.

(c)The process in which oxygen is added or hydro gen is removed.

(d)A metallic oxide which can be reduced into metal by hydrogen.

Q. Which of the given metals exhibits both reactions (a) as well as (b)?

(a) Metal + Oxygen $\to$ Metal oxide

(b) Metal + Cold water or hot water or steam $\to$ Metal hydroxide + Hydrogen

Q. Name the following:
(i) The kind of elements that ionize by losing electrons.
(ii) The kind of elements that ionize by gaining electrons.
(iii) Two metals that do not get oxidized at high temperature.
(iv) Two metals that get oxidized just by exposure to air.
(v) Three metals that react with cold water to liberate hydrogen.
(vi) A metal which in the red hot state reacts with steam reversibly to produce hydrogen.
(vii) Two metals that react explosively with acids.
(viii) A metal that does not react with hydrochloric or sulphuric acid.
(ix) Two metals that dissolve only in aqua regia.
(x) Two metallic oxides that get decomposed by heat.
(xi) Two metallic hydroxides that dissolve in water to give alkalis.
(xii) Two metal carbonates which are soluble in water.
(xiii) Two metal carbonates that do not decompose when heated.
(xiv) Two metallic nitrates which yield oxygen as the only gaseous product when heated.
(xv) Two metallic nitrates when heated decompose to yield respective metals.

Q. Metal X does not give hydrogen gas when allowed to react with cold or hot water but it reacts with steam to form metal oxide and hydrogen gas. Metal X cannot be

Q. A metal oxide having formula $Z_2{O}_3$ gives free metal and water on reduction with hydrogen. $0.2$ g of the metal oxide can be completely reduced by $12$ mg of hydrogen. The atomic weight of the metal is:

Q.

Name:

(a) the processes involved in

(i) concentration (ii) refining of ores.

(b) two metallic oxides which cannot be reduced by carbon, carbon monoxide or hydrogen.