Properties of Water – Maharashtra Board Class 7 Solutions for General Science (English Medium)
Water shows anomalous expansion. As the temperature increases from 0°C to 4°C, the density of water increases. The density of water is maximum at 4°C. The surface layer of water in a reservoir freezes at 0°C. However, the temperature of water below the ice is about 4°C. Hence, the water stays below the ice and the aquatic animals in the reservoir can survive in it.
Seawater consists of about 35 grams of salt per litre. Thus, the density of seawater is more than that of the ordinary water. Hence, this makes a person to swim with more ease in the seawater than in the ordinary water.
Water is said to be a universal solvent because many substances dissolve in it.
Water is a colourless, odourless, transparent liquid at normal temperature. It is a chemically neutral substance which makes it an ideal medium for most chemical reactions.
- The density of water is 1 g/cc.
- A substance that dissolves in a liquid is called a solute.
- When a solute and a solvent mix in each other completely, we get a solution.
|Group ‘A’||Group ‘B’|
|(a) Anomalous expansion||2. Water|
|(b) Density||1. Mass/Volume|
|(c) Dead Sea||4. 25% salt|
|(d) Water||3. Compound|