Chemistry

2. Negatively charged and found in all atoms
4. The total number of protons and neutrons in an atom
6. A special block of metalic elements with atomic numbers 90-103
7. Negativity charged ion
9. Also known as electron shells
13. The centre of an object
18. Attraction of positive and negative ions
19. In group 18
22. A special block of metalic elements from group 3-12
25. What represents an atom
27. An electron that can participate in the formation of a chemical bond
31. A particle representing a quantum of light or other electromagnetic radiation
32. A group of atoms formed by elections being transferred from one atom to another

1. The idea that electrons orbit around the nucleus at set distances
3. A special block of metalic elements on the periodic table with atomic numbers 58-71
5. A particle that makes up all material
8. Found in all atoms but has no charge
10. The lowest energy arrangement of an atoms electrons
11. Positively charged ion
12. Another term for semimetal
14. Arrangement of electrons in an electron shell
15. Surrounds the nucleus of an atom
16. A state of a physical system that is higher in energy than the ground state
17. The out most shell of an atom
20. Horizontal rows on the periodic table
21. Group 17 elements
23. Different forms of the same element
24. Group 1 elements
26. The number of protons in an atom
28. A substance composed of atoms with the same atomic number
29. Something that is composed of two or more elements
30. A column in the periodic table