Name the most common ore of the metal aluminum from which the metal is extracted. Write the chemical formula of the ore.

How is this forest of great commercial value to India?

A sound wave travelling in water has wavelength 0.4 m. Is this wave audible in air? (The speed of sound in water = 1400 ms^-1)

The ore of Uranium found in nature contains ₉₂U²³⁸ and ₉₂U²³⁵. Although both the isotopes are fissionable, it is found out experimentally that one of the two isotopes is more easily...

The period between 1920 to 1947 was marked with major events and reforms that finally led us to our Independence. In this context, Mention any four clauses of the Cabinet Mission Plan.

Conversion of ethanol to ethene by the action of concentrated sulphuric acid is an example of ____ . (dehydration / dehydrogenation / dehydrohalogenation)

(i) Why is a nuclear fusion reaction called a thermo nuclear reaction?

(ii) Complete the reaction:

³He₂ + ²H₁ → ⁴He₂ + .... + Energy

Name the natural vegetation found in the following regions: The western slopes of the Western Ghats.

1. What do you understand by a lone pair of electrons?
2. Draw the electron dot diagram of Hydronium ion. (H=1; O=8)?

Give a reason: Trees must be planted in the industrial areas

When can the Speaker of the Lok Sabha cast his vote?

State two factors upon which the rate of emission of thermions depends.

State the dependence of angle of deviation:

1. On the refractive index of the material of the prism.
2. On the wavelength of light.

Addition of ethyl alcohol to acetic acid in the presence of concentrated Sulphuric acid.

Burning of ammonia in air.

Name the following: An oil refinery in Bihar.