English Medium इयत्ता ९ - CBSE Question Bank Solutions for Science

Infrasound can be heard by

The biotic component of the biosphere is not constituted by

All the living organisms are basically made up of C, N, S, P, H and O. How do they enter the living forms? Discuss.

In agricultural practices, higher input gives a higher yield. Discuss how?

Write the modes by which insects affect the crop yield.

Give reasons:

A wooden table should be called a solid.

What is meant by a substance?

List the points of differences between homogeneous and heterogeneous mixtures with examples.

Which separation technique will you apply for the separation of the following?

Tea leaves from tea.

Which separation technique will you apply for the separation of the following?

Wheat grains from husk.

Classify each of the following as a homogeneous or heterogeneous mixture.

Soda water, wood, air, soil, vinegar, filtered tea.

In a reaction, 5.3 g of sodium carbonate reacted with 6 g of acetic acid. The products were 2.2 g of carbon dioxide, 0.9 g water and 8.2 g of sodium acetate. Show that these observations are in agreement with the law of conservation of mass.

Sodium carbonate + acetic acid → sodium acetate + carbon dioxide + water

Hydrogen and oxygen combine in the ratio of 1:8 by mass to form water. What mass of oxygen gas would be required to react completely with 3 g of hydrogen gas?

Which postulate of Dalton’s atomic theory is the result of the law of conservation of mass?

Why is it not possible to see an atom with naked eyes?

If bromine atom is available in the form of, say, two isotopes `""_35^79Br (49.7%)" and """_35^81Br (50.3%)`, calculate the average atomic mass of bromine atom.

The average atomic mass of a sample of an element X is 16.2 u. What are the percentages of isotopes `""_8^16X" and """_8^18X` in the sample?

What do you mean by free fall?

What do you mean by acceleration due to gravity?

Gravitational force acts on all objects in proportion to their masses. Why then, a heavy object does not fall faster than a light object?