Across
- 5. A substance that cannot be separated or broken down into simpler substances by chemical means
- 6. An arrangement of the elements in order of their atomic numbers
- 8. The number of protons in the nucleus of an atom
- 9. A subatomic particle that has no charge
- 10. A subatomic particle that has a positive charge
Down
- 1. A subatomic particle that has a negative charge
- 2. A horizontal row of the periodic table
- 3. The smallest unit of that maintains the properties of an element
- 4. A column in the periodic table of the chemical elements
- 7. The sum of the numbers of protons and neutrons present in the nucleus of an atom