Sound — Science STD 9 — Question

Which one of the following is not the unit of energy?

If 1.4g of calcium oxide is formed by the complete decomposition of calcium carbonate, then the amount of calcium carbonate taken and the amount of carbon dioxide formed will be respectively:

1. 2.2g and 1.1g
2. 1.1g and 2.5g
3. 2.5g and 1.1g
4. 5.0g and 1.1g

Which of the following process/ processes release heat?

1. Condensation.
2. Vaporization.
3. Freezing.
4. Melting.

1. Only (i)
2. Only (iv)
3. (i) and (iii)
4. (ii) and (iv)

Which one of the following is the fastest growing carp?

The number of valence electrons in a sulphide ion, S^2-, is:

1. 16
2. 10
3. 9
4. 8

Which of the following is not an element?

The phylum of sedentary animals is:

1. Mollusca.
2. Echinodermata.
3. Porifera.
4. Both (a) and (b).

Poultry farming is practiced for _______________:

1.008 grams of hydrogen combines with 35.453 g of chlorine to form 36.463 g of a pure compound (hydrogen chloride). Dalton's explanation for this experimental fact might be: 

Preventive and control measures adopted for storage of grains include.