Is Matter Around Us Pure — Science STD 9 — Question

The number of Al³⁺ ions in 0.051g of aluminium oxide are (Atomic mass of Al = 27u, O = 16u).

‘A’ has 9 protons, 9 electrons and 10 neutrons. 'B' has 12 protons, 12 electrons and 12 neutrons. Formula between A and B is:

The anion of an element has:

The best evidence for the existence and movement of particles in liquids was provided by:

1. John Dalton.
2. Ernest Rutherford.
3. J.J. Thomson.
4. Robert Brown.

Molecular compounds are usually formed by the combination between:

Tincture of iodine has antiseptic properties. This solution is made by dissolving:

1. Iodine in potassium iodide.
2. Iodine in acetone.
3. Iodine in water.
4. Iodine in alcohol.

Determine the number of electron in the isotope of 'H' (mass no. 2).

What would you observe when an aqueous sugar solution is heated to dryness:

The amount of energy required to change 1 kg of a solid into liquid at atmospheric pressure at its melting point is known as _______________?

On converting 308K, 329K and 391K to Celsius scale, the correct sequence of temperatures will be:

1. 33°C, 56°C and 118°C
2. 35°C, 56°C and 119°C
3. 35°C, 56°C and 118°C
4. 56°C, 119°C and 35°C