unit 4: reactions
Across
- 2. / a chemical reactions in which a substance reacts rapidly with oxygen, often producing heat and light.
- 5. / A change ( chemical) that requires or absorbs heat.
- 7. / A change (chemical reactions) that releases heat.
- 8. / A compound breaks down into 2 or more simpler substances(one thing becoming 2 or more.
- 11. Replacement / a chemical reaction in which two compounds exchange positive ions and form two new compounds.
- 12. Equation / a representation of a chemical reaction in which the reactants and products are expressed as formulas
- 14. Rate / the rate at which reactants change into products overtime
Down
- 1. / A number in front of a chemical formula in an equation that indicates how many molecules or atoms of each reactant and product are involved in a reaction.
- 3. / the number that is written below the element that lets you know the amount of atoms it has.
- 4. / a substance that undergoes change in a chemical reaction
- 6. Replacement / a chemical reaction in which one element takes the place of another element in a compound.
- 9. / (chemistry) a substance that initiates or accelerates a chemical reaction without itself being affected
- 10. / the combination of 2 or more substances to form a compound (things combining together to become one.
- 13. / new substances formed as a result of a chemical reaction