Page 30 - Ranger PT3 2022 science

Science PT3 Chapter 4 Reactivity of Metals

4.1 Variety of Minerals

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Various Forms of Minerals in the Earth’s Crust
1. Minerals are solid elements or compounds that exist naturally in the Earth’s crust.
2. All minerals have specific chemical compositions and structures.
3. Table 4.1 shows examples of minerals found in Earth’s crust.
Table 4.1
Elements Compounds
Gold, silver, diamond Bauxite, galena, hematite
4. Natural compounds are the combination of several elements. Table 4.2 shows natural
compounds and the elements found in them.

Table 4.2 Natural compounds, scientific names and combinations of elements
Common name Scientific name Combination of elements
Bauxite (Aluminium ore) Aluminium oxide Aluminium, oxygen
Hematite (Iron ore) Iron(III) oxide Iron, oxygen
Galena (Lead ore) Lead(II) sulphide Lead, sulphur
Cassiterite (Tin ore) Stanum(IV) oxide Tin, oxygen
Quartz Silicon dioxide Silicon, oxygen
Pyrite Iron(II) sulphide Iron, sulphur
Calcite Calcium carbonate Calcium, carbon, oxygen
5. The activity below shows that natural compounds are the combination of several
elements.

Boiling tube P Boiling tube Q
Test tube Test tube

Calcium
carbonate
Retort Retort
Calcium carbonate stand Limewater Limewater
and hydrochloric Heat stand
acid

Reaction with acid Reaction with heat
Diagram 4.1
Results:
Activity Observation
Reaction with acid Limewater turns cloudy Form 3
Reaction with heat Limewater turns cloudy
Form 3

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04 Ranger Science Ting.3.indd 270 30/03/2022 2:21 PM