Property which is same for the following species is:

 N^3–, O^2–, F^–, Na⁺, Mg²⁺ and Al³⁺ 

1. Ionic radii

2. Number of electrons

3. Nuclear charge

4. None of the above 

The ejection of the photoelectron from the silver metal can be stopped by applying a voltage of 0.35 eV when the radiation having a wavelength of 256.7 nm is used. The work function for silver metal is 

1. 3.40 eV

2. 5.18 eV

3. 4.48 eV

4. -4.40 eV

The ionization energy for H atom in the ground state is 2.18 x 10^-18 J. The process energy requirements will be: \(( He^+(g) \rightarrow He^{2+}(g) + e^- )\)
1. 8.72 x 10^-18 J
2. 7.54 x 10^-18 J
3. 5.67 x 10^-17 J
4. 2.18 x 10^-17 J

The maximum number of emission lines obtained when the excited electron of the H atom jumps from n = 6 to the ground state is -

1. 30

2. 21

3. 15

4. 28

Electrons are emitted with zero velocity from a metal surface when it is exposed to radiation of wavelength 6800 Å. The work function (W₀ ) of the metal is 

1. 3.109 x 10^-20 J

2. 2.922 x 10^-19 J

3. 4.031 x 10¹⁹ J

4. 2.319 x 10^-18 J

The total number of electrons present in one mole of methane is

$$\begin{gathered} 1. 6.023 \times {10}^{23} \\ 2. 6.023 \times {10}^{24} \\ 3. 6.023 \times {10}^{22} \\ 4. 1.619\times {10}^{23} \end{gathered}$$

The total number and mass of neutrons in 7 mg of ¹⁴C would be 

(Assume that mass of a neutron = 1.675 × 10^–27 kg)

$$\begin{gathered} 1. 2.41 \times {10}^{21} , 4.03 \times {10}^{–6} \mathrm{kg} \\ 2. 6.23 \times {10}^{23} , 1.67 \times {10}^{-21}\mathrm{kg} \\ 3. 1.22 \times {10}^{22} , 4.03 \times {10}^6 \mathrm{kg} \\ 4. 2.41 \times {10}^{21} , 4.03 \times {10}^{-6} \mathrm{g} \end{gathered}$$

The wave number of a light whose time period is 2.0 × 10^–10 s would be

1. 16.66 m^-1

2. 1. 66 m^-1

3. 32.34 m^-1

4. 12.34 m^-1

The number of photons of light with a wavelength of 4000 pm that provide 1J of energy would be 

$$\begin{gathered} 1. 2.01 \times {10}^{16} \\ 2. 2.01 \times {10}^{19} \\ 3. 4.14 \times {10}^{23} \\ 4. 2.14 \times {10}^{21} \end{gathered}$$

Electromagnetic radiation of wavelength 242 nm is just sufficient to ionise sodium atom. The ionisation energy of sodium in kJ mol^-1 is -

1. 494

2. 4.94

3. 516

4. 0.50