Name: Physical and Chemical Changes Explained
Uploaded: 2019-07-19
Duration: 5 min 35 s
Description: Millions of changes happen around us. These changes can be physical changes or chemical changes. Do you know the difference between them? Learn how to distin...

Question

Across:

1. This changes are usually temporary.

2. This brown layer is formed on the surface of iron objects.

3. A chemical change is also called ____ reaction.

Down:

1. The brown colour substance on iron objects is soft and ____.

3. These are definite substances with definite geometrical shape.

4. The process of coating a layer of zinc on iron objects.

Accepted Answer

Across:

1. Physical changes are usually temporary. A change in which no new substances are formed is a physical change. These changes are generally reversible.

2. When iron is exposed to the air for a longer duration, it reacts with oxygen and moisture present in the air and forms a brown powdery substance on the surface of iron called rust.

3. Changes in which the chemical properties of matter changes i.e. a new chemical substance is formed as a result of the change is known as chemical change. A chemical change is also called chemical reaction.

Down:

1. When iron is exposed to the air for a longer duration, it reacts with oxygen and moisture present in the air and forms a brown powdery substance on the surface of iron called rust, it leads to the decrease in strength of iron material. Hence, iron becomes soft and porous.

2. Crystals are the purest solid form of a substance having a definite geometrical shape. In a crystal, the constituent atoms, molecules, or ions are packed in a regularly ordered, repeating three-dimensional pattern. Formation of the crystal depend largely on factors such as temperature, air pressure, etc.

3.The galvanisation is a process of protecting iron or steel from rusting by coating them with a thin layer of zinc.

Dhiren M Doshi Solutions for Chapter: Physical and Chemical Changes, Exercise 2: CROSSWORD PUZZLE

Dhiren M Doshi Science Solutions for Exercise - Dhiren M Doshi Solutions for Chapter: Physical and Chemical Changes, Exercise 2: CROSSWORD PUZZLE

Questions from Dhiren M Doshi Solutions for Chapter: Physical and Chemical Changes, Exercise 2: CROSSWORD PUZZLE with Hints & Solutions

Learn and Prepare for any exam you want !