Page 80 - SCERT Kerala State Syllabus 8th Standard Basic Science Textbooks English Medium Part 1_Neat

Extended Activities

1. Take iron powder and sulphur powder in their mass ratio of
7:4 in a china dish. Heat it strongly for some time.

(a) Try to separate the iron powder using a magnet. What
can be observed? What is the reason?
(b) Add a little dilute hydrochloric acid to the above
product; observe the changes taking place, and write
them down.
(c) Write down the inferences you have arrived at from these
observations.

2. Make and exhibit the models of the following molecules using
ball and sticks, different fruits and splints.
(a) Water (H O)
2
(b) Ammonia (NH )
3
(c) Carbon dioxide (CO )
2
(d) Methane (CH )
4
(3) Haven't you understood how symbols are assigned to
elements? Given below are some elements that received
symbols from their Latin names. Complete the table with the
help of the Periodic Table.

Element Latin name Symbol
Silver ............... ...............

............... Hydrargium ...............
Tin ............... ...............
............... ............... Pb

Antimony ............... ...............
............... Aurum ...............

Basic Science VIII
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