"Atomic Crossword": HTML5 Crossword

Across

2. a collective name for the protons and neutrons - (8)
8. mass of an atom, protons + neutrons, can be expressed as atomic mass units (amu) - (6,4)
10. spectrum of frequencies of electromagnetic radiation emitted due to an atoms electrons making a transition from a high energy state to a lower energy state, can be used to identify elements - (7)
13. no charge, same number of protons and electrons - (12,7)
16. positively charged particle inside the nucleus of an atom - (6)
17. zones within the electron cloud where electrons are likely to be, each zone can contain a certain number of electrons, - (6,5)
18. atoms of the same element which have different numbers of neutrons - (7)

Down

1. neutral particle inside the nucleus with no charge - (7)
3. hypothetical charge atom would have if all bonds to atom were ionic - (9,5)
4. average mass of an atom of an element, derived from weighted percentages of all the isotopes of the atom - (6,6)
5. an object with a surplus of charge either negative or positive - (7,6)
6. common notation used to indicate the atomic number and mass number of an isotope - (7,8)
7. theory about the structure of the atom, the atom is composed of a small positively charged nucleus surrounded by a large electron cloud - (6,6)
9. also known as the proton number, number of protons in an atom, the atomic number determines which element the atom is - (6,6)
11. small particles of an atom that surround the nucleus in the electron cloud, negatively charge, weight is too small to be counted in the atomic mass - (8)
12. surrounds the nucleus and contains the electrons - (8,5)
14. dense small center of an atom, contains the protons and neutrons, surrounded by the electron cloud - (6,7)
15. one of the 4 fundamental forces in nature, holds together the nucleons in the nucleus - (6,5)