- Atoms consist of electrons surrounding a nucleus that contains protons and neutrons.
- The number of electrons in the outermost shell has a direct link to the group number that the element is found in.
- Protons have a mass number of 1, and a charge of +1.
- Neutrons have a mass number of 1, and a charge of 0.
- Electrons have an extremely small mass number, and a charge of -1.
- The mass number is the TOP NUMBER.
- The atomic number is the BOTTOM NUMBER.
- Elements consist of one type of atom only.
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- Ions are electrically charged particles formed when atoms lose or gain electrons.
- Metal atoms lose electrons to become postively charged ions.
- Non-metal atoms gain electrons to become negatively charged ions.
- The strong forces of attraction between oppositely charged ions are called ionic bonds.
- These strong forces therefore require a lot of energy to be broken, and consequently ionic bonds have high melting and boiling points.
- SHARING ELECTRONS - covalent bonding.
- TRANSFERRING ELECTRONS - ionic bonding.
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