Across
- 1. the result of a chemical reaction.
- 7. a way of expressing information about the proportions of atoms that constitute a particular chemical compound, using a single line of chemical element symbols, numbers, and sometimes also other symbols, such as parentheses, dashes, brackets, commas and plus (+) and minus (−) signs
- 8. states that for any system closed to all transfers of matter and energy, the mass of the system must remain constant over time, as system mass cannot change quantity if it is not added or removed
- 9. occur when objects or substances undergo a change that changes the physical form of a composition but not the chemical composition.
- 10. occur when a substance combines with another to form a new substance, called synthesis or, alternatively, decomposes into two or more different substances. In general, are not reversible except by further chemical reactions.
- 11. a lasting attraction between atoms that enables the formation of chemical compounds.
Down
- 2. the symbolic representation of a chemical reaction in the form of symbols and formulas.
- 3. odorless, colorless, monatomic gases with very low chemical reactivity
- 4. An electron in an outer shell of an atom that can participate in forming chemical bonds with other atoms
- 5. a substance that takes part in and undergoes change during a reaction.
- 6. a group of elements in the periodic table. They are all in the first column of the periodic table. They are extremely reactive.