Mass Number

Q.

Hydrogen molecule is represented as --------.

Q. Which of the following are true for an element?

1. Atomic number = number of protons + number of electrons
2. Mass number = number of protons + number of neutrons
3. Atomic mass = number of protons = number of neutrons
4. Atomic number = number of protons = number of electrons

Q.

The molecular mass of $C{H}_{3}C{H}_{2}OH$ is ______.

1. 50 u

2. 35 u

3. 70 u

4. 46 u

Q.

Atomicity is the combining capacity of an element.

1. True
2. False

Q.

Homoatomic molecules

Q.

Define the molecular mass of the substance.

Q. Arrange the molecules in the increasing order of molecular weight from top to bottom.

1. $\mathrm{CO}$
2. ${\mathrm{CO}}_2$
3. $\mathrm{CaO}$
4. ${\mathrm{CaCO}}_3$

Q. Amongst the following, which has the highest molecular mass?

1. $C{l}_2$
2. $N_2$
3. $C{H}_{3}OH$
4. $N{H}_3$

Q. The relative molecular mass of a substance expressed in grams is known as _____________.

1. gram molecular mass
2. average atomic mass
3. gram atomic mass
4. average molecular mass

Q. Which among the following is the chemical symbol for iron?

1. K
2. Fe
3. Zn
4. Na

Q.

Avogadro's Number is the no. of atoms present in ____ of Carbon C-12.

1. 10g (gram atomic weight)

2. 12g (gram atomic weight)

3. 1g (gram atomic weight)

4. 8g (gram atomic weight)

Q.

Between the elements- $\mathrm{N},\mathrm{O},\mathrm{P}\mathrm{and}\mathrm{S}$; the one with the maximum atomicity is?

1. $\mathrm{N}$

2. $\mathrm{O}$

3. $\mathrm{P}$

4. $\mathrm{S}$

Q. Consider the following statements:
(a) Molecular mass of $C{H}_{3}OH$ is $32u.$
(b) In $N{H}_3$, the ratio of $N$ and $H$ by mass is $14:3.$
(c) The formula mass of $CaC{l}_2$ is $111u.$
(d) Isotopes have same mass number.

1. $\text{(a) and (c)}$
2. $\text{(a), (b) and (d)}$
3. $\text{(a), (c) and (d)}$
4. $\text{(a), (b) and (c)}$

Q. The atomic mass of carbon is:

1. 12 u
2. 24 u
3. 32 u
4. 6 u

Q. The molecular mass of $N{H}_3$ is ________.

1. 10 u
2. 16 u
3. 18 u
4. 17 u

Q.

If an atom A has a mass number 'x' and atomic number 'y' ( $A_y^x$ ) and it forms an ion $A^{-1}$ by losing an electron. What can we say about the mass number of the ion?

1. Mass number will be equal to x

2. Mass number will be lesser than x

3. Mass number varies randomly

4. Mass number will be greater than x

Q.

The atomicity of the element argon is ______.

1. one

2. two

3. three

4. four

Q. Which of the following is correct with respect to the mass ratio of the combining elements in the compound - $C_2{H}_{5}OH$?

1. Ratio of C:H:O is 8:3:12
2. Ratio of C:H:O is 6:2:1
3. Ratio of C:H:O is 2:6:1
4. Ratio of C:H:O is 12:3:8

Q.

What is mass number?

1. Sum of protons and electrons

2. Sum of protons and neutrons

3. None of these

4. Sum of electrons and neutrons