Periodic Table Crossword

2. a subatomic particle with a neutral electric charge.
4. a tabular array of the chemical elements organized by atomic number
6. column of elements on a periodic table
7. row of chemical elements on a periodic table
10. any long pairs of electrons and bonding groups.
13. a chemical substance that cannot be broken down into other substances.
16. the average mass of the atoms of an element measured in atomic mass unit.
18. elements which form negative ions
19. average mass of the atoms of an element

1. a positively charged region at the center of an atom
3. basic building block of chemistry
4. the physical and chemical properties of elements are arranged in increasing order of their atomic numbers in periodic function.
5. atoms with the same number of protons but different numbers of neutrons.
8. a measure of how much a substance reacts when it is mixed with another substance.
9. a subatomic particle with a negative electric charge.
11. an element intermediate in properties between the typical metals and nonmetals.
12. the outside part of an atom around the atomic nucleus.
14. a substance that has no fixed shape or size.
15. the characteristic ability of a substance to react to new substances.
17. a subatomic particle with a positive electric charge.
20. any of a class substance characterized by high electrical and thermal conductivity