1. Fill in the blanks with the appropriate
term.
(Temperature, volume, mass, density,
humidity, acidic, weight, neutral, shape.)
(a) The capacity of air to hold moisture
depends upon the ......... of the air.
(b) Water does not have a .............
but has definite .......... and .......... .
(c) While freezing, the .................... of
water is lowered.
(d) ................. soil has pH 7.
2. Why is it said that -
(a) Air is a homogeneous mixture of
various gases.
(b) Water is a universal solvent.
(c) There is no alternative to water for
cleaning purposes.
3. What will happen if.....
(a) The amount of water vapour in the
air increases.
(b) Only one crop is grown repeatedly
in the soil.
4. With whom should I pair up?
Group ?A? Group ?B?
(1) Air (a) Excretion
(2) Water (b) Scattering of light.
(3) Soil (c) Plasticity
5. State whether the following statements
are true or false.
(a) Sandy soil has low capacity for
holding water.
(b) The substance in which a solute
dissolves is called a solvent.
(c) The pressure exerted by air is called
atmospheric pressure.
6. Explain the picture in your own
words.
t t t
Water
7. Write answers to the following
questions in your own words.
(a) How is light scatterred by the air ?
(b) Explain the various properties of
water.
(c) Why is the density of seawater
more than that of rain water ?
(d) What is the importance of good soil
structure ?
(e) What are the various uses of soil ?
(f) What is the need and importance
of soil testing from the point of
view of farmers ?
(g) What is the importance of air in
transmission of sound ?
(h) Why should a glass bottle completely
filled with water never be kept in
a freezer ?