Chemical Patterns Revision

1. Chemical Patterns Revision

2. Atomic Structure • Atoms consist of protons, neutrons and electrons. • Each element has a different number of protons. • The number of protons and electrons is the same in an atom. • Elements are arranged in order in the periodic table. • All elements in the same group have the same number of electrons in the outer shells. • All elements in the same period fill a shell with electrons. • Use electron configuration diagrams.

3. Group 1 – Alkali Metals • Lithium<Sodium<Potassium • React with water produce hydrogen and alkaline hydroxides. • React with chlorine to produce crystalline salts. • Understand that some chemicals are harmful and precautions should be taken.

4. Formulae and Equations • Know the formulae for Hydrogen, water, halogens and group 1 halides and hydroxides. • Write balanced equations. • Using state of matter symbols, g,s,l,aq

5. Group 7 - Halogens • Recognise symbols and molecules of group 7 halogens. • Recall colours and physical states of the halogens. • Recall that halogens are bleaches and kill bacteria. • Fluorine>chlorine>Bromine>Iodine • Safety precautions when handling halogens.

6. Spectra • Elements emit distinctive colour and spectra. • This can be used to identify or discover elements. • Some elements would not have been discovered but for the use of spectra.

7. Ionic Theory • Compounds of group 1 and group 7 elements are ionic. • Their ions are arrange in a giant ionic lattice. • When molten or dissolved in water, ionic compounds of metals with non-metals conduct electricity. • Their ions are free to move when liquid.

8. Ions • An ion is an atom that has gained or lost an electron. • Work out the charge on an ion based on the chemical formula and vice versa.