Atoms and Molecules — Science STD 9 — Question

Which of the following are isotopes and which are isobars?
Argon (Ar), Deuterium (D), Calcium (Ca), Tritium (T), Protium (P)

All matter that is present in the universe has:

Which of the following cannot be separated from air by the process of fractional distillation?

1. Oxygen.
2. Argon.
3. Hydrogen.
4. Nitrogen.

Four students A, B, C and D verified the law of conservation of mass by performing chemical reaction between barium chloride and sodium sulphate. All of them took 107.2g barium chloride solution and 116.1g of sodium sulphate solution and mixed them in the beaker of mass 150g. They reported their results as follows:

Students	Colour of reaction mixture after mixing	Mass of reation mixture in the beaker including mass of beaker
A	White Precipitate	383.3g
B	BrownPrecipitate	393.3g
C	WhitePrecipitate	373.3g
D	Brown Precipitate	363.3g

The correct observation is that of student.

Name a technique used to separate.Petrol and water:

It is an ionic compound:

One of the following does not show Tyndall effect. This one is:

1. Soap solution.
2. Ink.
3. Sugar solution.
4. Starch solution.

Match column I with the column II.

	Column I		Column II
A.	Solution	I.	Chalk in water
B.	Colloid	II.	Tincture of iodine
C.	Suspension	III.	Starch in water
D.	Homogeneous	IV.	A mixture of chalk and sand
E.	Heterogeneous	V.	Air

The size of the nucleus is approximately:

In water, the proportion of oxygen and hydrogen by mass is:

1. 1 : 4
2. 1 : 8
3. 4 : 1
4. 8 : 1