Question

In the following set of substances, one item does not belong to the set. Select this item and explain why it does not belong to the set Hydrogen, Oxygen, Steam, Chlorine

Answer 1

Steam

Explanation:

• We are given set of four substances, Hydrogen, Oxygen, Steam, Chlorine.

• We are asked to find out the one which doesnt belong to the set.
• We see that hydrogen ,oxygen, chlorine exist at elements in their bi state.

$H_{2} ,O_{2} ,Cl_{2}$

• Steam is product of water at high temperatures. This is obtained from boiling water after supplying latent heat of vapourization.
• So steam here is a compound made up of different elements.It has the formula of water in gaseous state.
• So as steam is a compound and others being elemental forms, steam doesnt belong to that set.

Answer 2

Steam is Not an Element

Explanation:

• Off the given list of substances --

Hydrogen, Oxygen, Steam and Chlorine

• Steam is the only odd one as rest all are elements with Hydrogen (Atomic Number - 1),

Oxygen (Atomic Number - 8) and Chlorine (Atomic Number -17)

• Steam can be referred to as vapor being produced by boiling of water.  

With change of state from Liquid to Vapor, the molecules become free and hence becoming steam.

• It can also be called as transformation of liquid to gas.