Atoms and the Periodic Table

5. The number of protons in the nucleus of an atom, which determines the chemical properties of an element and its place in the periodic table.
7. A positively charged subatomic particle that is found in the nucleus of an atom.
8. The smallest unit of matter.
9. The region of negative charge surrounding an atomic nucleus that is associated with an atomic orbital.
10. A chart of the chemical elements that displays them in rows horizontally in order of increasing atomic number and vertically according to similarity of the chemical properties of their atoms.
12. A New Zealand-born British physicist that discovered that atoms have a small charged nucleus surrounded by largely empty space.
13. An American physicist that discovered the value for electron charge through the famous oil-drop experiment.
14. The vertical column in the periodic table; elements in this column have similar physical and chemical properties.

1. The mass of an atom of a chemical element expressed in AMU. (Protons+ Neutrons)
2. The horizontal row of elements in the periodic table, atomic number and mass increases across this row.
3. A group of atoms held together by a chemical bond.
4. An English physicist that proved that the unique identity of every element depends on the number of protons it has.
6. A subatomic particle that is found in the nucleus of an atom and has no charge.
11. A Danish physicist that proposed a model of the atom in which the electron was able to occupy only certain orbits around the nucleus using the quantum theory.
12. A negatively charged subatomic particle that is found in orbitals outside the nucleus.