Atoms and Molecules — Science STD 9 — Question

Cathode rays have:

Nitrogen and hydrogen combine together to form ammonia.
N₂ + 3H₂ → 2NH3 [Relative atomic masses of N = 14u, H = 1u]
The mass of nitrogen and hydrogen which combine together to form 6.8g ammonia is,

Four elements W, X, Y and Z contain 8, 11, 9 and 17 protons per atom respectively. The element which cannot form an anion is most likely to be:

1. W
2. X
3. Y
4. Z

Compounds formed by metals and non-metals contain charged species which are known as:

What was the source of alpha particles in Rutherford scattering experiment?

Which of the following is not a mixture?

1. Kerosene.
2. Air.
3. Alcohol.
4. Petrol.

Which of the following is/are true as per Thomson's model of atom:

One of the following substances is neither a good conductor of electricity nor an insulator. This substance is:

Neon and chlorine have atomic numbers 10 and 17 respectively. Their valencies will be ______ and ______ respectively:

A student wants to have 3.011 × 10²³ atoms each of magnesium and carbon elements. For this purpose, he will have to weigh:

1. 24g of magnesium and 6g of carbon.
2. 12g of carbon and 24g of magnesium.
3. 20g of magnesium and 10g of carbon.
4. 12g of magnesium and 6g of carbon.