According to Moseley, a straight-line graph is obtained on plotting-

1. The frequencies of characteristic X-rays of elements against their atomic numbers.

2. The square of the frequencies of characteristic X-rays of elements against their atomic numbers

3. The square root of the frequencies of characteristic X-rays of elements against their atomic numbers

4. The reciprocal of the frequencies of characteristic X-rays of elements against their atomic numbers.

The tenth element in the periodic table resides in:

1. the second period

2. the fourth period

3. the fifth period

4. the eight period

Which of the following order is not in accordance with the property stated against it?                                                                                                      

1. F₂ > Cl₂ > Br₂ > l₂ Oxidising Power

2. Hl > HBr >HCl >HF Acidic property in water

3. F₂ > Cl₂ > Br₂ > l₂ Electronegativity

4. F₂ > Cl₂ > Br₂ > l₂ Bond dissociation energy

An element X occurs in short period having configuration ns²np¹ . The formula and nature of its oxide are:

1. XO₃, basic

2. XO_3, acidic

3. X₂O₃, amphoteric

4. X₂O₃, basic

The outermost electronic configuration of the most electronegative element is :

1. ns²np³

2. ns²np⁴

3. ns²np⁵

4. ns²np⁶

The elements X, Y, Z and J have the indicated electron configurations starting with the innermost shell. The most metallic element is :

1. X = 2, 8, 3

2. Y = 2, 8, 8

3. Z = 2, 8, 8, 1

4. j = 2, 8, 8, 7

Which statement is true?

1. The electronegative nature of elements increases along the period

2. The electropositive nature of elements increases along the period

3. The chemical reactivity of elements increases along the period

4. The I.E  of element decreases along the period

The most non-metallic element among the following is:

1. Be

2. B

3. Mg

4. Al

₅₈Ce is a member of which block?

1. s-block elements.

2. p-block elements.

3. d-block elements.

4. f-block elements.

The screening effect of 'd' electrons is:

1. Much less than s-electrons.

2. Much more than s-electrons.

3. Equal to s-electrons.

4. Equal to p-electrons.