Acids, Bases and Salts — Science STD 10 — Question

The Chipko Andolan was associated with saving of tigers.

State whether the following statements are true or false:

1. The scattering away of red light makes the sky appear blue during the day time.
2. The scattering away of blue light makes the sun appear red at sunset.

One can identify the nature of a mirror from the nature of the image it forms. [True/ False]

State whether the following statement is true or false:
Only 10 per cent of the light energy given by the sun is available for transfer at each higher trophic level in a food chain.

The solid and liquid fuels which do not vaporise on heating, burn without producing a flame. [True/ False]

Non-biodegradable wastes are the major pollutants of the environment.

Ultimate cause of variations among living beings is alteration in DNA sequence in the genes. [True/ False]

Impression of an event stays in the mind for 1/24 of a second. [True/ False]

State whether the following statements are true or false:
According to Mendeleev’s periodic law, the properties of elements are a periodic function of their atomic numbers.