Matter in Our Surroundings — Science STD 9 — Question

A sample of pure water, irrespective of its source, contain 11.1% hydrogen and 88.9% oxygen. The data supports:

In a sample of ethyl ethanoate (CH₃COOC₂H₂), the two oxygen atoms have the same number of electrons but different number of neutrons. Which of the following is the correct reason for it?

When light is passed through water containing a few drops of milk, it shows a bluish tinge. This is due to the scattering of light by milk. This indicates that milk is :

The formula of a compound is X₃Y. The valencies of elements X and Y will be respectively:

The Latin language name of an element is natrium. The English name of this element is:

The atomicities of ozone, sulphur, phosphorus and argon are respectively:

The inter-particle attractive force ______ with increasing distance between particles.

Which of the following has a direct effect on the kinetic energy of particles:

Which of the following represents a correct chemical formula?

1. CaCl
2. Na₃N
3. NaSO₄
4. NaS

When a mixture of iron powder and sulphur powder is heated strongly to form iron sulphide, then heat energy is:

1. Released.
2. First absorbed and then released.
3. Absorbed.
4. Neither absorbed nor released.