Sources of Energy — Science STD 10 — Question

We often observe domestic waste decomposing in the bylanes of our homes. List four ways to make the residents aware that the improper disposal of wastes is harmful to the environment and also for their own health.

Potatoes grow well on Anhad’s farm which has soil with a pH of 5.5. Anhad decides to add lot of lime to soil so that he can grow broccoli in the same farm:

1. Do potatoes grow better in acidic or alkaline soil?
2. Does broccoli grow better in acidic or alkaline soil?

Name the two types of spherical mirrors. What type of mirror is represented by the:

1. Back side of a shining steel spoon?
2. Front side of a shining steel spoon?

State two ways in which the current induced in the coil of a generator could be increased.

An element A has 4 valence electrons in its atom whereas element B has only one valence electron in its atom. The compound formed by A and B does not conduct electricity. What is the nature of chemical bond in the compound formed? Give its electron-dot structure.

The atomic numbers of three elements A, B and C are given below:

Element	Atomic Number
A	5
B	7
C	10

1. Which element belongs to group 18?
2. Which element belongs to group 15?
3. Which element belongs to group 13?
4. To which period/ periods do these elements belong?

Write any two points about good source of energy?

What will happen if a solution of sodium hydrocarbonate is heated? Give the equation of the reaction involved.

A first-aid manual suggests that vinegar should be used to treat wasp stings and baking soda for bee stings. What does this information tell you about the chemical nature of:

1. Wasp stings?
2. Bee stings?