Properties of Alkali Metals

Q.

Why does lead doesn't react with water?

Q.

Both helium(He) and beryllium (Be) have two valence electrons. But helium is inert gas and zero valent whereas beryllium shows a valency of 2.

Q.

Question 14
Differentiate between metal and non-metal on the basis of their chemical properties.

Q.

Sodium can be cut by a knife, so it is a metalloid.

1. True

2. False

Q.

(a) Why are alkali metals kept in kerosene oil?

(b) What is :

(i) basic lead carbonate and

(ii) brown powder deposit on iron?

(c) Why is hydrogen kept in the metal activity series?

Q.

$Be$ has 2 electrons in its outer shell, $O$ has 6 electrons in its outer shell. Choose the correct option:

1. Be and O have valency 1 and 6 respectively

2. Be and O have valency 1 and 2 respectively

3. Be and O have valency 1 and 7 respectively

4. Be and O have valency 2 and 2 respectively

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. The alkali metal that can combine directly with nitrogen when heated in air is:

1. $Li$
2. $Na$
3. $Cs$
4. $K$

Q.

(a) Why are alkali metals kept in kerosene oil?

(b) What is :

(i) basic lead carbonate and

(ii) brown powder deposit on iron?

(c) Why is hydrogen kept in the metal activity series?

Q. Metals which do not react with dilute acids:

1. $Cu$
2. $Ag$
3. $Hg$
4. All of these

Q. Alkali metals have one electron in their valence shell.

1. True
2. False

Q.

Which of the following elements shows variable valency?

1. Nickel

2. Sodium

3. Helium

4. Carbon