Is Matter Around Us Pure ? — Science STD 9 — Question

Biological weathering is caused by:

1. Lichens.
2. Mosses.
3. Roots of plants.
4. All the above.

The element which is not common between the compounds called baking soda and soda ash is:

1. Sodium.
2. Hydrogen.
3. Oxygen.
4. Carbon.

The anion in CaCl2​ is:

In a natural ecosystem, decomposers include:

1. Bacteria and fungi.
2. Parasitic algae.
3. Macroscopic animals.
4. All the above.

Assertion: Cells vary greatly in their shape.
Reason: The shape of cell does not depend on the function they perform.

Redwood tree of california reaches a height of:

1. 25m.
2. 50m.
3. 75m.
4. 100m.

The frequency of sound waves in water is:

A bullet of mass 10g moving with a velocity of 400m/s gets embedded in a freely suspended wooden block of mass 900g. What is the velocity acquired by the block?

Which of the following atom has a valency of three:

Simple tissues are these:

1. Parenchyma, xylem and collenchymas.
2. Parenchyma, collenchymas and sclerenchyma.
3. Parenchyma, xylem and sclerenchyma.
4. Parenchyma, xylem and phloem.