Chemistry Crossword

1. Ionic compounds always have a crystal _______ structure.
4. Covalent compounds have _____ bonds.
6. these kinds of substances contain one type of atom.
7. An atom is mainly made out of _____ space.
9. Orange juice is an example of a ___________ mixture.
11. Ionic compounds usually have _____ melting and boiling points.
15. A type of homogeneous mixture that has microscopically dispersed particles between one to a thousand nanometers.
16. Carbon, Oxygen, and Hydrogen must all be present in this reaction.
18. Unexpected color change, release of energy, and unexpected temperature change are all _______ of a chemical change.
19. 2H2 + O2 → 2H2O is an example of a _______ reaction.
20. _______ compounds are formed when the electrons from metals are transferred over to nonmetals.
21. the center of the atom where protons and neutrons are found.

2. In chemicals equations both sides must be balanced to achieve _______.
3. A type of mixture that is not uniform in terms of composition.
5. Pure substances include elements and _______.
8. These types of mixture are not evenly distributed and can be separated by a physical process.
10. Melting ice cream is an example of this type of change.
12. A type of chemical bond formed when atoms share electrons.
13. __Al + 3O2 → 2Al2O3 (write it in word form).
14. Most nonmetals that form ionic bonds have _____ to seven valence electrons.
17. C2H4 + 3O2 → __CO2 + 2H2O (write it in word form).