Cheat Sheet Metals and Non-metals - Science Class 10 PDF Download
1. Classification of Elements
Elements can be classified into metals and non-metals based on their physical and chemical properties.
Examples:
- Metals: Iron, copper, aluminium, zinc
- Non-metals: Carbon, sulphur, oxygen, hydrogen
Metals and non-metals differ in their appearance, conductivity, and reactions with other substances.
2. Physical Properties of Metals
Metals generally have the following physical properties.
Metallic Lustre
Metals have a shiny surface when freshly cut or polished. This shiny appearance is called metallic lustre.
Example: Gold and silver are highly lustrous metals.
Hardness
Most metals are hard, although the hardness varies.
Example:
- Iron is hard
- Sodium is soft and can be cut with a knife
Malleability
The ability of metals to be beaten into thin sheets is called malleability.
Example: Gold and silver are the most malleable metals.
Ductility
The ability of metals to be drawn into thin wires is called ductility.
Example:
- Gold is the most ductile metal.
- 1 gram of gold can be drawn into a wire about 2 km long.
Conductivity
Examples: Copper and silver are very good conductors.
Sonority
Metals produce a ringing sound when struck, a property known as sonority.
Example: School bells are made of metals.
3. Physical Properties of Non-metals
Non-metals generally show properties opposite to metals.
Examples of non-metals:
- Carbon
- Sulphur
- Iodine
- Oxygen
4. Exceptions in Properties
Some elements do not follow the general properties.
Examples:
- Mercury - metal but liquid at room temperature
- Iodine - non-metal but lustrous
- Graphite (carbon) - conducts electricity
- Sodium and potassium - very soft metals
Therefore, elements cannot always be classified only on physical properties.
5. Chemical Properties of Metals
Reaction with Oxygen
Metals react with oxygen to form metal oxides.
General reaction: Metal + Oxygen → Metal oxide
Examples:
2Cu + O₂ → 2CuO
4Al + 3O₂ → 2Al₂O₃
Most metal oxides are basic in nature.
Amphoteric Oxides
Some metal oxides show both acidic and basic properties.
Examples:
- Aluminium oxide (Al₂O₃)
- Zinc oxide (ZnO)
These oxides react with both acids and bases.
6. Reaction of Metals with Water
Metals react with water to form metal hydroxide and hydrogen gas.
General reaction: Metal + Water → Metal hydroxide + Hydrogen
Examples:
2Na + 2H₂O → 2NaOH + H₂
Ca + 2H₂O → Ca(OH)₂ + H₂
However, not all metals react with water.
Potassium and sodium react very violently, so they are stored in kerosene oil.
7. Reaction of Metals with Acids
Metals react with dilute acids to produce salt and hydrogen gas.
General reaction: Metal + Dilute acid → Salt + Hydrogen gas
Example: Zn + 2HCl → ZnCl₂ + H₂
Note:
- Copper does not react with dilute hydrochloric acid.
- Nitric acid usually does not produce hydrogen gas because it is a strong oxidising agent.
8. Reaction with Metal Salt Solutions
A more reactive metal displaces a less reactive metal from its compound.
Example: Fe + CuSO₄ → FeSO₄ + Cu
This is called a displacement reaction.
9. Reactivity Series
The reactivity series arranges metals in order of decreasing reactivity.
Important rule:
Metals above hydrogen can displace hydrogen from acids.
10. Ionic Compounds
When metals react with non-metals, electrons are transferred and ionic compounds are formed.
Example: Na + Cl → NaCl
Here:
- Sodium loses an electron → Na⁺
- Chlorine gains an electron → Cl⁻
These oppositely charged ions attract each other to form an ionic bond.
11. Properties of Ionic Compounds
They do not conduct electricity in solid state because ions cannot move freely.
12. Occurrence of Metals
Metals occur naturally in the earth's crust as minerals.
Examples:
- Bauxite → Aluminium ore
- Haematite → Iron ore
13. Extraction of Metals
Extraction methods depend on the reactivity of the metal.
Activity series and related metallurgyExamples:
- Sodium → Electrolysis
- Iron → Reduction using carbon
- Mercury → Heating ore
Steps involved in the extraction of metals from ores
14. Corrosion
Corrosion is the slow destruction of metals due to reaction with air, moisture, or chemicals.
Examples:
- Rusting of iron
- Green coating on copper
- Black coating on silver
Rusting occurs only when both air and water are present.
Investigating the conditions under which iron rusts. In tube A, both air and water are present. In tube B, there is no air dissolved in the water. In tube C, the air is dry.
15. Prevention of Corrosion
Methods used to prevent rusting include:
- Painting
- Oiling or greasing
- Galvanisation (zinc coating)
- Chrome plating
- Alloying
Example: Stainless steel is an alloy of iron, chromium and nickel.
16. Alloys
An alloy is a homogeneous mixture of two or more metals or a metal with a non-metal.
Examples:
Alloys often have better strength, corrosion resistance, and durability.
FAQs on Cheat Sheet: Metals and Non-metals
| 1. What are the physical properties of metals and non-metals? |  |
| 2. How do ionic compounds differ from covalent compounds? | |
| 3. What is the process of extraction of metals from their ores? | |
| 4. What causes corrosion in metals, and how can it be prevented? | |
| 5. What are alloys, and why are they important? | |
