Structure of atoms: protons,electrons and neutrons

Protons and neutrons

• The protons are the positive charge in the nucleus of an atom
• The neutrons are also in the nucleus but they have no charge
• The mass of neutrons is the same as that of protons
• Neutrons and protons have the same mass
• Neutrons have no charge
• Protons have a positive charge
• The particles in the nucleus i.e the protons and the neutrons are known as nucleons
• The number of nucleons is known as the nucleon number

Electrons

• Electrons have a negative charge
• They circle around the nucleus in fixed orbits called electronic shells
• The mass of an electron is much smaller than that of a proton

Atoms

• Atoms have no charge
• They are electrically neutral
• This is because the number of protons and electrons is always equal
• The negative and positive charges cancel each other

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