The minerals from which metals can be extracted profitably and conveniently are called ores. Most metals are extracted from their ores found in the Earth's crust. Minerals are extracted from the earth by the process called mining. For example, bauxite is an ore of aluminium that contains compounds of aluminium like aluminium oxide with other impurities.

The property by virtue of which metals can be drawn into thin wires is called ductility. Gold and silver are two of the most ductile metals known. Other metals that can be drawn into wires include copper, aluminium, and tungsten.

Take a strip of aluminium foil and dip it in dilute hydrochloric acid solution. Do you see bubbles rising in the solution? What do the bubbles contain?

When a strip of aluminium foil is dipped in a dilute hydrochloric acid solution, it reacts with the hydrochloric acid solution, causing gas bubbles to rise in the solution. When a strip of aluminium foil is dipped in a dilute hydrochloric acid solution, the aluminium displaces hydrogen from the hydrochloric acid, forming an aluminium chloride salt along with the liberation of hydrogen gas. This is due to the fact that aluminium is more reactive than hydrogen. The bubbles that form are hydrogen gas bubbles.

Slow destruction of metals due to chemical reactions on their surface by oxygen, carbon dioxide, moisture, sulphur dioxide, hydrogen sulphide, etc., present in the atmosphere, is known as corrosion.

Write names of any two metalloids.

The elements which show some properties of metal and other properties of non-metal, which means they show the properties of both metals and non-metals are called metalloids. The examples of metalloids are the following: (I) Silicon (II) Germanium (III) Arsenic

E M B I B E

GALAXY SCIENCE IN EVERYDAY LIFE>Chapter 4 - Metals and Non-metals>ORAL QUESTIONS>Q 3

EASY

8th CBSE

IMPORTANT

Earn 100

What is an ore?

Important Questions on Metals and Non-metals

EASY

8th CBSE

IMPORTANT

GALAXY SCIENCE IN EVERYDAY LIFE>Chapter 4 - Metals and Non-metals>ORAL QUESTIONS>Q 4

What is ductility?

MEDIUM

8th CBSE

IMPORTANT

GALAXY SCIENCE IN EVERYDAY LIFE>Chapter 4 - Metals and Non-metals>ORAL QUESTIONS>Q 5

Give any four physical properties of metals.

HARD

8th CBSE

IMPORTANT

GALAXY SCIENCE IN EVERYDAY LIFE>Chapter 4 - Metals and Non-metals>Activity Questions>Q 1

Rub a piece of lime on the dull surface of a metal object. Keep it for some time. Wash off the lime. Then take a piece of cloth and polish the surface until the metal shines.

Question Image
1. Does the metal regain its lustre?
2. Does lime contain acid?
3. Does an acid react with a metal oxide?