Curriculum
Science — First Preparatory
Unit 1: Matter
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Unit 2: Forces
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Unit 3: Life
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Unit 4: Earth and Space
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Text lesson
Structure of the Atom
Structure of the Atom
The basic particles of the atom
The basic particles of the atom
- The atom is the smallest part of an element that keeps the chemical properties of that element.
- It consists of a small nucleus at the centre, surrounded by electrons that move in energy levels.
- The nucleus is made of protons and neutrons.
| Particle | Charge | Relative mass (approximately) | Location |
|---|---|---|---|
| Proton | +1 | 1 | Inside the nucleus |
| Neutron | Zero (neutral) | 1 | Inside the nucleus |
| Electron | −1 | Less than 1 ÷ 1800 | Outside the nucleus, in energy levels |
- In a neutral atom the number of electrons equals the number of protons
- so the positive and negative charges balance.
Structure of the Atom · 1 / 6