SSC CGL - Detailed Guide 2025
Self-Paced Course
Matter and Its Nature
Reference: Lucent GK, NCERT Class 6–12
1. States of Matter
| State | Shape | Volume | Compressibility | Particle Arrangement | Example |
|---|---|---|---|---|---|
| Solid | Fixed | Fixed | Negligible | Tightly packed, regular | Ice, Iron, Wood |
| Liquid | No fixed | Fixed | Slight | Loosely packed, mobile | Water, Oil, Alcohol |
| Gas | No fixed | No fixed | High | Far apart, very mobile | Air, Oxygen, CO₂ |
| Plasma | No fixed | No fixed | Very High | Ionized particles, high energy | Sun, Lightning, Neon signs |
Note: Plasma is the most abundant state in the universe (e.g., stars).
2. Physical and Chemical Changes
| Type of Change | Nature of Change | Reversibility | New Substance Formed | Energy Change | Example |
|---|---|---|---|---|---|
| Physical Change | Change in form/appearance | Usually yes | No | Low or none | Melting ice, Boiling water |
| Chemical Change | Change in composition | No | Yes | Often heat/light released | Rusting of iron, Burning paper |
Physical changes are temporary; chemical changes are permanent and involve bond formation/breaking.
3. Elements, Compounds, and Mixtures
Elements
- Pure substances made of only one kind of atom.
- Cannot be broken down into simpler substances by chemical means.
| Type | Example |
|---|---|
| Metals | Iron (Fe), Copper (Cu) |
| Non-metals | Oxygen (O), Sulfur (S) |
| Metalloids | Silicon (Si), Boron (B) |
Compounds
- Substances formed by chemical combination of two or more elements in a fixed ratio.
- Properties of compound are different from its constituent elements.
| Compound | Formula | Composition |
|---|---|---|
| Water | H₂O | Hydrogen + Oxygen |
| Carbon Dioxide | CO₂ | Carbon + Oxygen |
| Sodium Chloride | NaCl | Sodium + Chlorine |
Mixtures
- Combination of two or more substances physically mixed.
- Components retain their individual properties.
| Type | Nature | Example |
|---|---|---|
| Homogeneous | Uniform throughout | Salt solution, Air |
| Heterogeneous | Non-uniform composition | Sand + Salt, Oil + Water |
Mixtures can be separated by physical methods (filtration, distillation, etc.).
Developed By Jan Mohammad
Next
Start Your SSC CGL Journey Now!
Join Courage Library to experience disciplined study and expert support.
Be a Couragian!