Periodic Classi...

In their attempts to classify the elements, which among the following scientists attempted to arrange them on the basis of similarity in properties alone?

According to Newlands law of octaves, beryllium resembles which of the following elements?

Which of the following laws was formulated by Mendeleev?

Lithium and sodium are placed in the same group of the Mendeleev's periodic table. Which of the following statements is/are the correct conclusion(s) drawn with regard to lithium and sodium?

(i) They have the same electronic configuration.
(ii) The formulae of their hydrides are the same.
(iii) The formulae of their oxides are the same.

In which of the following pairs does the second element have a lesser electron affinity than the first?

Identify the incorrect statement about the ionisation energy.

An element with atomic number 10 belongs to:

The existence of which of the following present day elements was predicted by Mendeleev and was named Eka Boron?

Which of the following pairs correctly represents the respective general formulae of oxides and hydrides made by all the elements of carbon group, as suggested by Mendeleev?