Across
- 3. - A number placed before a chemical formula in an equation to show how many molecules or atoms take part.
- 6. - A statement based on repeated experimental observations that describes some aspect of the world.
- 7. - A process in which substances change into new substances.
- 9. - A substance with a distinct composition that can be involved in a chemical reaction.
- 12. - When a compound or molecule does not change easily.
- 16. - A combination of symbols that shows the elements in a compound and their proportions.
- 17. - The principle that matter cannot be created or destroyed in a chemical reaction.
- 18. - A substance made of only one kind of atom.
- 19. - A substance made from two or more different elements chemically combined.
Down
- 1. - Related to matter and energy but not involving a change in chemical composition.
- 2. - A substance formed as a result of a chemical reaction.
- 4. - A symbolic representation of a chemical reaction showing reactants and products.
- 5. - To make the number of atoms of each element equal on both sides of a chemical equation.
- 8. - The amount of matter in an object or substance.
- 10. - A group of two or more atoms bonded together representing the smallest unit of a compound.
- 11. - A small number written to the lower right of an element symbol showing how many atoms of the element are in the molecule.
- 13. - The smallest unit of an element that retains the properties of that element.
- 14. - A substance that starts a chemical reaction.
- 15. - The process where substances interact and change to form new substances.