Page 45 - Chemistry_Form_2

Chemistry
for Secondary Schools

Note: The way electronic configurations of strontium and barium (Table 2.7)
are written is beyond the scope of this book. However, for the sake of
understanding this section, the electronic configurations are written to
show the period number, group number, and their relations to the trends.

FOR ONLINE READING ONLY
Group II elements have the following properties:
Physical properties
(a) They are harder metals than those in Group I.
(b) They are silvery-grey in colour when pure and clean. However, they tarnish
quickly when left in the air due to the formation of the respective metal
oxides.

(c) They are good conductors of heat and electricity.
Chemical properties

(a) They burn in oxygen or air with a characteristic flame colour to form a
solid white oxide.

(b) They react with water but much less vigorously than the elements in Group I.

(c) The reactivity of metals increases down the group. For example, the
reaction of calcium with water is vigorous, while that of magnesium with
water is relatively slow.

Activity 2.2

Aim: To demonstrate the differences in reactivity of calcium and magnesium
with water

Requirements: Two test tubes, magnesium ribbon, calcium, distilled water, and
measuring cylinder
Procedure

1. Transfer about 5 cm of distilled water in a test tube.
3
2. Add a small amount of calcium (half spatulaful) from the container in
which it is stored. Record your observations.

3. Repeat Steps 1 and 2 using a clean piece of magnesium ribbon. Record
your observations.

38 Student’s Book Form Two

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CHEMISTRY FORM TWO NEW 2025 DUMMY.indd 38
CHEMISTRY FORM TWO NEW 2025 DUMMY.indd 38 01/08/2025 11:20:53