Chemistry-1

4. Reactive Group-2 metals
5. Highly reactive Group-1 metals
6. A substance made of only one type of atom
11. The negatively charged subatomic particle that orbits the nucleus of an atom
12. The positively charged subatomic particle in the nucleus of an atom
13. A substance made of more than one element
15. An atom that has lost or gained electrons and therefore carries a charge

1. Group 17 non-metal
2. Horizontal row of the periodic table
3. Vertical column of the periodic table
7. Metals in Groups 3 to 12 inclusive
8. Forms of an element with different atomic mass
9. Group 18 inert gas
10. The property of an element that determines the number of other atoms with which an atom of the element can combine
14. The subatomic particle of neutral charge in the nucleus of an atom