Page 72 - Science Class 06

S r gently to allow the solid to dissolve. In this ac vity, you would have no ced
S r each glass with its spoon only. that the five different substances dissolve

Con nue to add and s r un l some solid to different degrees in water. We say that
remains at the bo om of the glass. some substances are soluble, while others
are insoluble. If a substance dissolve easily
How many spoons did you have to add in
in water, we say it is highly soluble in
I, II, III, IV and V, before that solid
water. If it remains as a solid in water even
dissolved completely? Record your
a er s rring hard, we call it insoluble.
findings in the observa on table.

Checking solubility or different solids:

Whether soluble
Type of solid Number of spoons
Glass No. (s) / partly soluble
dissolved which are dissolved
(PS) or insoluble (I)

I Salt

II Sugar

III Sand

IV Mud

V Baking soda

TWO MUSTS FOR A CHANGE Interac on
Whatever be the type of a change– slow or No change can take place at all, anywhere,
in any manner, unless there is an interac on
fast, good or bad, temporary or permanent,
between two things or among more than
reversible or irreversible, periodic or non-
two things. For example, if we cut an apple
periodic and physical or chemical, two
with a knife, the knife and the apple
things are essen ally involved in this
interact. Both of them undergo change as
process. They are—interac on and energy.
well. Whereas the apple gets cut in more

72 Science-6