Across
- 3. compound with chemical formula H2SO4
- 8. a _________ is the purest form of a substance
- 9. when two or more elements combine in a definite proportion to form a new substance known as _________
- 10. element with symbol Na
Down
- 1. _________ and electrons are electrically charged
- 2. atoms consists of ________ surrounding a nucleus
- 4. properties such as shape, size, and colour of a substance are called its ___________ properties
- 5. substance that participates in a chemical reaction
- 6. element with symbol Fe
- 7. the number of protons in an atom is called its _______ number