Which isotopes of hydrogen has no neutrons?

1. Protium

2. Deuterium

3. Tritium

Which of the statements given above is/are correct?

Consider the following statements regarding hard water:

$1$. Water free from calcium and magnesium salts like bicarbonates, chlorides, and sulphates, is called hard water.

$2$. Hard water does not lather with soap.

$3$. Hard water is harmful to boilers.

Which of the statements given above is/are incorrect?

Hard water is harmful to boilers. Why?

1. The salts present in hard water deposited in the inner surface of boilers and decreases the efficiency of boilers.

2. The salts present in hard water deposited on the outer surface of boilers and decreases the efficiency of boilers.

Which of the statements given above is/are correct?

Consider the following statements regarding the hydrogen economy:

1. The main aim of a hydrogen economy is to transmit energy in the form of hydrogen, not as electric power.

2. Hydrogen as a fuel has many advantages over conventional fuel in that, it is not polluting, and it can be stored and transported easily.

Which of the statements given above is/are correct?

What is the role of ultraviolet (UV) radiation in the water purification systems? 

1. It inactivates/kills the harmful microorganisms in water.

2. It removes all the undesirable odours from the water.

3. It quickens the sedimentation of solid particles, removes turbidity and improves the clarity of water.

Which of the statement(s) given above is/are correct?

Consider the following statements with reference to the periodic table of chemical elements:

1. Ionization potential gradually decreases along a period.

2. Atomic size increases along a period.

3. In a given period, electronegativity decreases as the atomic number increases.

Which of the statement (s) given is/are correct?

Consider the following statements,

$1$. The number of periods in the modern periodic table is $7$.

$2$. The number of groups in the modern periodic table is $18$.

$3$. The long form of the periodic table was developed by Range and Werner.

Which of the statements given above is/are correct?

Consider the following statements:

1. Liquid hydrogen is used as rocket fuel.

2. Nascent hydrogen is not a reactive and powerful oxidizing agent.

3. In ortho hydrogen, the spins of both nuclei are in the same direction.

Which of the statement (s) given above is/are correct?