Classification ...

Why do noble gases have positive electron gain enthalpy?

As we move from left to right, the electronegativity increases. An atom which is highly electronegative has

Study the given diagram and fill up the blanks with appropriate choice.

Fill in the blanks with the appropriate option. 
The ability of an atom to attract shared electrons to itself is called (i). It is generally measured on the (ii) scale. An arbitrary value of (iii) is assigned to fluorine (have greatest ability to attract electrons). It generally (iv) across a period and (v) down a group.

In which of the following, the order is not in accordance with the property mentioned.

Choose the incorrect statement.

In the periodic table, the maximum chemical reactivity is at the extreme left (alkali metals) and extreme right (halogens). Which properties of these two groups are responsible for this?

An element X has atomic number 19. What will be the formula of its oxide?

An element 'P' has atomic number 56. What will be the formula of its halide?

Predict the formula of stable compound formed by an element with atomic number 114 and fluorine.

Predict the formula of a compound formed by aluminium and sulphur.

There are many elements in the periodic table which exhibit variable valency. This is a particular characteristic of

Predict the formulae of the binary compounds formed by combination of the following pairs of elements:
(i) Magnesium and nitrogen
(ii) Silicon and oxygen

The first element of the groups 1 and 2 are different from other members of the respective groups. Their behaviour is more similar to the second element of the following groups. What is this relationship known as?

The main reason for showing anomalous properties of the first member of a group in s or p-block is

When we go from left to right in a period,

Which of the following oxides is neutral in nature?

What is the common property of the oxides CO, NO and N₂O?

The correct order of acidic character of oxides in third period of periodic table is

Which of the following sets of oxides is amphoteric in nature?

(A), (B) and (C) are elements in the third short period. Oxide of (A) is ionic, that of (B). is amphoteric and of (C) a giant molecule. (A), (B) and (C) have atomic number in the order ;

What is common between given cations and anions, O2^-, F^-, Na⁺, Mg²⁺, Al³⁺?

Which of the following is arranged in order of increasing metallic character?

Which is the most electropositive element?

Among the elements with atomic numbers 9, 12, 16 and 36 which is highly electropositive?