ELEMENTS AND COMPOUNDS

C3 Atoms elements and compounds

C3.1 Physical and chemical changes

1. IDENTIFY physical and chemical changes and understand the differences between them

UNDERSTAND that some chemical reactions can be reversed by changing the reaction conditions

C3.2 Elements, compounds and mixtures

2. DESCRIBE the difference between elements, mixtures and compounds, and between metals and non-metals

3. DEFINE the term solvent, solute, solution and concentration

C3.3 Atomic structure and the periodic table

1. DESCRIBE the structure of an atom in terms of central nucleus, containing protons and neutrons and "shell" of electrons

2. DESCRIBE the build-up of electrons in shell and understand the significance of the noble gas electronic structures and of the outer shell electrons

3. STATE that charges and approximate relative masses of protons, neutrons and electrons

C3.3 Atomic structure and the periodic table

1. DEFINE and USE the atomic number

2. DEFINE and USE the mass number

3. USE atom number and the simple structure of atoms to explain the basis of Periodic Table (first 20 elements)

4. DEFINE isotope as atoms of the same element which have same atomic number but different mass number

5. UNDERSTAND that isotopes have the same properties because they have the same number of electrons in the outer shell

C3.4 Chemical bonding in elements and compounds

1. DESCRIBE the formation of ions by electrons loss or gain

2. USE dot-and-cross diagrams to describe the formation of ionic bonds between Group I and Group VII

3. (supplement) I - DESCRIBE the formation of ionic bonds between metallic and non-metallic elements to include the strong attraction between ions because of their opposite electrical charges

4. (supplement) II - DESCRIBE the lattice structure of ionic compounds as a regular arrangement of alternating positive and negative ions, exemplified by the sodium chloride structures

C3.5 Molecule and covalent bonds

1. STATE that non-metallic elements form simple molecule with covalent bonds between atoms

2. DESCRIBE the formation of single covalent bonds in H2, Cl2, H2O, CH4, NH3 and HCl as the sharing of pairs of electrons leading to the noble gas configuration including the use of dot-and-cross diagrams

3. DESCRIBE the differences in volatility, solubility and electrical conductivity between ionic and covalent compounds.

C3.5 Molecule and covalent bond

1. (supplement) I - USE AND DRAW dot-and-cross diagrams to represent the bonding in the more complex covalent molecules such as N2,C2H4, CH3OH and CO2.

2. (supplement) II - EXPLAIN the differences in the melting point and boiling point of ionic and covalent compounds in terms of attractive forces.

C3.6 Macromolecules

1. STATE that there are several different forms of carbon, including diamond and graphite

2. DESCRIBE the giant covalent structures of graphite and diamonds

3. (supplement) RELATE the structures of diamonds and graphite to heri use e.g. graphite as a lubricant and a conductor and diamond in cutting tools

4. (supplement) DESCRIBE the macromolecular structure of silicon (IV) and oxide (silicon dioxide, SiO2)