Which of the following statements about the electron is incorrect?

1.	It is a negatively charged particle.
2.	The mass of electron is equal to the mass of neutron.
3.	It is a basic constituent of all atoms. ​​​
4.	It is a constituent of cathode rays.

The number of radial nodes for 3p orbital is :

1. 3

2. 4

3. 2

4. 1

Which pair of ions has the same electronic configuration?

Match the quantum numbers with the information provided by these numbers:

Choose the correct codes:

1. A-(ii),B-(iii),C-(iv),D-(i)

2. A-(ii),B-(iv),C-(i),D-(iii)

3. A-(ii),B-(i),C-(iv),D-(iii)

4. A-(ii),B-(iii),C-(i),D-(iv)

Identify the pairs which are not isotopes?

(a) \(_{6}^{12}X, \ _{6}^{13}Y\)

(b) \(_{17}^{35}X, \ _{17}^{37}Y\)

(c) \(_{6}^{14}X, \ _{7}^{14}Y\)

(d) \(_{4}^{8}X, \ _{5}^{8}Y\)

1. (a), (d)
2. (b), (c)
3. (c), (d)
4. (b), (d)

The nuclei of which one of the following pairs are isotones:

The quantum number of four electrons are given below : 

The correct order of their increasing energies is:
1. I < III < II < IV
2. IV < II < III < I
3. I < II < III < IV
4. IV < III < II < I

 In \(_{35}^{80}Br\), $$the number of protons, neutrons, and electrons are:${}_{\mathrm{}}{}^{\mathrm{}}$

1. 25, 45, 45

2. 35, 45, 35

3. 45, 45, 35

4. 80, 35, 35

Find the de Broglie wavelength of a ball of mass 0.1 kg moving with a velocity of 10 m s⁻¹.

1. 662.6 × 10^–34 m

2. 66.26 × 10^–34 m

3. 6.626 × 10^–34 m

4. 6.626 × 10^–36 m

The total number of orbitals associated with the principal quantum number n = 3 are :

1. 3

2. 6

3. 9

4. 12