Chemistry-C1 1

Chemistry-C1 1

1. Atoms,elements + compounds

   • elements only contain 1 type of atom
   • has a tiny nucleus in its centre, surrounded by electrons
   • compounds contain 2 or more types of atoms
   • all substances are made up of atoms

2. Atomic structure

   • protons and neutrons in nucleus
   • protons=positive
   • electrons=negative
   • arranged in order of atomic number on periodic table
   • number of protons + neutrons =mass number

3. electron in atoms

4. bonds

   • Ionic
   • covalent
   • metallic

5. equations

   • no new atoms are created or destroyed
   • total mass of reactants = total mass of products