Across
- 3. laws of chemical combination
- 5. an ion with a negative charge
- 6. a reference to calculate atomic mass
- 9. atomic mass 14
- 10. element with symbol Ca
- 11. a metal with valency +1
- 14. the Latin name for sodium
- 15. = number of electrons
- 16. = 6.022 × 10^23 particles .
- 17. have atoms of same chemical properties
Down
- 1. number of atoms in a molecule of an element
- 2. A positively charged ion
- 4. combination of different atoms in a fixed ratio by mass
- 7. smallest particles of all the matter
- 8. a monoatomic gas
- 12. gave the atomic theory
- 13. remains unchanged before and after a chemical reaction
- 14. gases that do not react at all
- 18. atomicity of oxygen