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?

A, B and C are the elements of a Dobereiner's triad. If the atomic mass of A is 7 u and that of C is 39 u, what should be the atomic mass of B?

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?

The numbers of groups in the s-block and p-block of the periodic table, respectively, are

The elements with atomic numbers 4, 12, 20, 38 and 56 belong to

The most metallic element in group 15 (nitrogen family) is

Group 15

N

P

As

Sb

Bi

Observe the elements of period III and select the strongest reducing and oxidising agents, respectively.

Na, Mg, Al, Si, P, S, Cl, Ar

Select the pair of amphoteric oxides from the following:

Which among the following is the smallest in size?

Which of the following is not correct about the modern periodic table?

Elements A, B and C have positions in the periodic table as shown below:

Group 16	Group 17
--------	--------
--------	A
--------	--------
B	C

(i) A is a metal.
(ii) C is smaller in size as compared to B.
(iii) Element A forms a negatively charged ion.

Which of the above statements is/are correct?

The bond in the compounds formed by the combination of group 14 and group 17 elements of the periodic table will be a/an

An element A belongs to third period and second group of the periodic table. The number of valence electrons of element A is