History of Periodic Table: Early Attempts at the Classification of Elements

An element P (atomic number 20) reacts with an element Q (atomic number 17) to form a compound. Answer the following questions giving reason:

Write the position of P and Q in the Modern Periodic Table and the molecular formula of the compound formed when P reacts with Q.

An element X (atomic number 17) reacts with an element Y (atomic number 20) to form a compound.

(a) Write the position of these elements in the modern periodic table.

(b) Write the formula of the compound formed.

Justify your answer in each case.

Write the electronic configuration of two elements X and Y whose atomic numbers are 20 and 17 respectively. Write the molecular formula of the compound formed when element X reacts with element Y. Draw the electron-dot structure of the product and also state the nature of the bond formed between both the elements.

Rewrite the following statement after correction, if necessary:

Groups have elements with consecutive atomic numbers.

Answer the following question.
Write the name, symbol, and electronic configuration of an element X whose atomic number is 11.

The element which can from an acidic oxide should be the one whose atomic number is:

(a) 6
(b) 16
(c) 12
(d) 19

The elements A, B and C belong to groups 1, 14, and 17 respectively of the periodic table.
(a) Which two elements will form a covalent compound?
(b) Which two elements will form an ionic compound?

The following diagram shows a part of the periodic table containing first three periods in which five elements have been represented by the letters a, b, c, d and e (which are not their chemical symbols):

1

18

a	2	13	14	15	16	17
		b					c
d						e

(i) Select the letter which represents an alkali metal.
(ii) Select the letter which represents a nobles gas.
(iii) Select the letter which represents a halogen.
(iv) What type of bond is formed between a and e?
(v) What type  of bond is formed between d and e?