physical and chemical change class 7

Which of the following is a physical change?

• Rusting of iron

• Melting of wax

• Combustion of magnesium ribbon

• Burning of candle

Tags

NGSS.MS-PS1-4

A chemical change may involve

• Change in color only

• Change in temperature only

• Evolution of gas only

• Any or all of the above

Tags

NGSS.MS-PS1-2

Which of the following processes is used to prevent articles from rusting?

• Crystallization

• Galvanization

• Evaporation

• Electolysis

Which of the following changes is accompanied by sound?

• Photosynthesis

• Spoilage of food

• Explosion of fire works

• Crumpling of paper

Choose the chemical change among the following

• 
• 
• 
• 

Hydrochloric acid is added to a beaker containing a piece of zinc. Zinc chloride is formed and hydrogen gas is released.This is an example of:

• chemical reaction

• physical change

• crystallisation

• none of these

Name the gas which turns lime water milky.

• carbon dioxide

• oxygen

• nitrogen

Which of the two is permanent change chemical change or physical change?

• physical

• chemical

• all of them

• none of them

i had a apple;i cut it and kept it for a while.my mom says that both physical and chemical changes had taken place.is she

• right

• wrong

What type of change is photosynthesis?

• physical change

• chemical change