Calculate the work function of silver metal, given that a stopping voltage of 0.35 eV is applied and the radiation has a wavelength of 256.7 nm.

1. 3.40 eV

2. 5.18 eV

3. 4.48 eV

4. –4.40 eV

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 ionization energy for H atom in the ground state is \(2.18 \times10^{-18}~ \mathrm J.\) The process energy requirements will be: \(( He^+(g) \rightarrow He^{2+}(g) + e^- )\)

Determine the maximum number of emission lines produced when an electron in a hydrogen atom transitions from the n = 6  energy level to the ground state :

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 × 10^–20 J

2. 2.922 × 10^–19 J

3. 4.031 × 10¹⁹ J

4. 2.319 × 10^–18 J

The statement that is not correct for periodic classification of elements is:

Comprehension given below is followed by some multiple choice questions. Each question has one correct option. Choose the correct option.

In the modern periodic table, elements are arranged in order of configuration. Depending upon the type of orbitals receiving the last electron, the elements in the periodic table have been divided into four block, viz s, p, d and f.

The modern periodic table consists of 7 periods and 18 groups. Each period begins with the filling of a new energy shell. In accordance with the Aufbau principle, the seven periods (1 to 7) have 2, 8, 8, 18, 18, 32 and 32 elements respectively.

The seventh period is still incomplete. To avoid the periodic table being too long, the two series of f-block elements, called lanthanoids and actinoids are placed at the bottom of the periodic table

(i) The element with atomic number 57 belongs to 

1. s-block

2. p-block 

3. d-block

4. f-block

The electronic configuration of the element which is just above the element with atomic number 43 in the same group is ______.

1. $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}3{\mathrm{d}}^{5}4{\mathrm{s}}^2$

2. $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}3{\mathrm{d}}^{5}4{\mathrm{s}}^{3}4{\mathrm{p}}^6$

3. $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}3{\mathrm{d}}^{6}4{\mathrm{s}}^2$

4. $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}3{\mathrm{d}}^{7}4{\mathrm{s}}^2$

The concept that contradicts the Bohr Model of an atom is: 

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