Tom week 6 vocabulary

2. horizontal row of the periodic table. There are seven periods in the periodic table, with each one beginning at the far left. A new period begins when a new principal energy level begins filling with electrons.
4. the number of protons in the nucleus of a atom; the atomic number is the same for all atoms of an element
6. a substance that cannot be separated or broken down into simpler substances by chemical means
8. A subatomic particle that has no charge and that is located in the nucleus of an atom.
10. The smallest unit of an element that maintains the properties of that element

1. an arrangement of elements in order of their atomic numbers such that elements with similar properties fall in the same column,or group
3. a subatomic particle with a positive electric charge.
5. a subatomic particle that has a negative charge
7. a column in the periodic table of the chemical elements.
9. the sum of the numbers of protons and neutrons present in the nucleus of an atom