(1)(a) The elements in Group
of the periodic table are known as the
metals because they form oxides or
which dissolve in water to give
solutions of
.
(b) They are metals with
density and the first three in the Group are less
than water, and so
.
(c) They have unusually low
points and the solids are quite
.
(2)(a) They react with non-metals to form
e.g. with oxygen to form
, sulfur to form
and
to form chlorides.
(b) These salt-like compounds are
solids which
in water to form
neutral solutions of
.
(c) The formula for sodium chloride is
, and sodium hydroxide is
.
(3)(a) The Alkali Metals react exothermically with water releasing
and forming soluble alkaline hydroxides.
(b) When a piece of
, sodium or potassium is placed in
water the metal
because of its low
.
(c) It and may melt and move around the surface with lots of
. The more reactive the metal, the
the reaction with water.
(d) A simple laboratory test for the
gas is that when a test tube of the gas is held to a
the gas burns in the air with a squeaky
.
(e) During the reaction
indicator will turn from
to
.
eg sodium + water ==>
+
(4) In Group 1, the further
the group with increase in
, the
reactive the alkali metal and the
its melting point and
point.
(5) When heated in a bunsen flame
metal or compounds give a yellow flame colour and
metal or compounds give a purple colour in a hot flame.