The students of class IX have made placards showing the symbols of some elements and valencies of these elements. These placards somehow got mixed up as shown below :

On this basis of these placards the chemistry teacher, Mrs. Shanti, asked a student Vikas to answer the following questions :
(a) Choose the symbol of an element from among the placards which exhibits valencies of 3 and 5. What is the name of is the name of this element ? Is it a metal or a non-metal ?
(b) Choose the symbol of an element from the given placards which shows a valency of 2. What is the name of this element ? Is it a metal or a non-metal ?
(c) Work out the formula of the compound formed between the element of valency 3 and element of valency 2. Also name this compound
(d) What values are displayed by Vikas in this episode ?

Explanation

(a) The symbol of element which exhibits the valencies of 3 and 5 is P. The name of this element is phosphorus. It is a non-metal
(b) The symbol of element which exhibits a valency of 2 is O. The name of this element is oxygen. It is also a non-metal
(c) The formula of compound formed between phosphorus element exhibiting a valency of 3 and oxygen element of valency 2 can be worked out as follows :

Thus, the formula of compound formed between phosphorus element of valency 3 and oxygen element of valency 2 is `P_(2)O_(3)`. The name of this compound is phosphorus trioxide
(d) The formula of compound formed between phosphorus element exhibiting a valency of 5 and oxygen element of valency 2 can be worked out as follows :

Thus, the formula of compound between phosphorus element of valency 5 and oxygen element of valency 2 is `P_(2)O_(5)`. The number of this compound is phosphorus pentoxide
(e) The values displayed by Vikas in this episode are (i) Knowledge of the symbols of elements and their valencies, and (ii) Ability to apply knowledge in solving problems.