Incorrect statement about metal is:

1. Metals can donate electrons.
2. Metals form ionic compounds.
3. Metals are more electronegative.
4. Metals have less ionization energy.

The group number that has non-metal, liquid as well as gas at room temperature, is -

Among the following elements, the one that is not an actinoid is:

The order of screening effect of electrons of s, p, d and f orbitals of a given shell of an atom on electrons in its outer shell is :

1. s > p > d > f

2. f > d > p > s

3. p < d < f < s

4. f > p > s > d

The first ionisation enthalpies of Na, Mg, Al, and Si are in the order of-

1. Na < Al < Mg < Si

2. Na > Mg > Al > Si

3. Na < Mg < Al < Si

4. Na > Mg > Al < Si

Among halogens, the correct order of amount of energy released in electron gain (electron gain enthalpy) is-

The period number in the long form of the periodic table is equal to : 

The elements in which electrons are progressively filled in 4f-orbitals are called:

The correct order of size of the given species is: 

1.  I > I^- > I⁺

2.  I⁺ > I^- > I

3.  I > I⁺ > I^-

4.  I^- > I > I⁺