Structure of an Atom

Q.

The atomic numbers of $Al,NaandBe$ respectively are:

1. 11, 13 and 4

2. 13, 11 and 6

3. 13, 6 and 11

4. 13, 11 and 4

Q.

If Avogadro's number is $6\times {10}^{23}$, then the number of protons, neutrons and electrons in 14 g of ${}_6{C}^{14}$ are respectively:

1. $36\times {10}^{23},48\times {10}^{23},36\times {10}^{23}$
   

2. $36\times {10}^{23},36\times {10}^{23},36\times {10}^{21}$
   

3. $48\times {10}^{23},36\times {10}^{23},48\times {10}^{21}$
   

4. $48\times {10}^{23},48\times {10}^{23},36\times {10}^{21}$

Q.

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

1. Mass number will be lesser than x

2. Mass number will be greater than x

3. Mass number will be equal to x

4. Mass number varies randomly

Q.

Rutherford’s experiment on scattering of $\alpha$ - particles showed for the first time that the atom has

1. electrons

2. protons

3. neutrons

4. nucleus

Q.

Which of the following is the correct representation of electrons, protons and neutrons respectively?

1. ${}_1^{0}e{,}_1^{-1}p{,}_0^{1}n$

2. ${}_{-1}^{0}e{,}_1^{1}p{,}_0^{1}n$

3. ${}_0^{1}e{,}_1^{1}p{,}_1^{1}n$

4. ${}_0^{1}e{,}_1^{1}p{,}_1^{0}n$

Q.

According to Dalton's atomic theory, matter consists of indivisible particles called atoms.

1. True

2. False

Q.

Discovery of the nucleus of an atom was due to the experiment carried out by

1. Mosley

2. Bohr

3. Rutherford

4. Thomson

Q.

Atoms achieve stable configuration by ____

1. Sharing electrons

2. Losing electrons

3. Gaining electrons

4. All of these

Q. Calculate the approximate atomic mass of oxygen atom $168O$ in the order of ${10}^{-26}$.

1. 2.672

Q. About how many times is an atomic nucleus smaller than the atom?

1. 1, 00, 000
2. 100
3. 10, 000
4. 1, 000