1 Principles of Chemistry (Single Award) (Part 2)

3. Neutral subatomic particle present in the nucleus of the atom. Relative mass of 1.
4. A row of the periodic table. Elements in the same period have the same number of electron shells.
7. forces which exist between molecules. The strength of the intermolecular forces impact physical properties like boiling/melting point.
9. Positively charged subatomic particle present in the nucleus of the atom. Relative mass of 1.
13. Unreactive. The noble gases are also described as being inert.
14. number of protons in the nucleus.
15. The smallest part of an element that can exist. All substances are made up of atoms. Atoms contain a positively charged nucleus surrounded by negatively charged electrons.
16. The strong forces of attraction between oppositely charged ions.
18. Elements that react to form positive ions. Found to the left and towards the bottom of the periodic table.

1. Particles smaller than an atom. Protons, neutrons and electrons are the three most common subatomic particles.
2. Table of elements arranged in order of increasing atomic number and such that elements with similar properties are in the same column (group).
5. A column of the periodic table. Elements in the same group have similar chemical properties.
6. charged object composed of protons and neutrons at the centre of every atom with one or more electrons orbiting it.
8. The elements in Group 0 of the periodic table. They have a stable full outer shell of electrons which makes them very unreactive.
10. Negatively charged subatomic particle which orbits the nucleus at various energy levels. Very small relative mass (negligible).
11. Elements that react to form negative ions. Found towards the right and top of the periodic table.
12. Different energy levels in atoms, occupied by electrons.
17. Atoms of the same element with the same number of protons but a different number of neutrons.