Unit A: Chemistry

2. in a chemical formula, this is represented by a single capital letter, or a single capital letter and a single lower case number
3. this type of reaction can produce a colour change, odor or light
7. this gas causes a glowing splint to reignite
9. type of material made by humans, such as nylon or polyester
11. in incomplete combustion, a lack of oxygen causes carbon ____ to be produced
15. a mixture of two or more different metals
17. the sound made when hydrogen gas is exposed to flame
18. a strong base used as a drain cleaner or to make soap
19. the products of this chemical reaction are carbon dioxide and water
20. burning coal releases large amounts of carbon _____

1. exothermic reactions will ______ thermal energy
4. in a lab the variable that is changed in each trial
5. chemicals written on the left hand side of the arrow in a chemical equation
6. chemicals written on the right hand side of the arrow in a chemical equation
8. in a lab the variable that is not changed
10. a chemical reaction where two elements combine to form a compound
12. when carbon dioxide is bubbled through this substance, it turns from clear to cloudy
13. in a chemical formula, this is represented by at least two capital letters
14. the type of chemical reaction occurring between and acid and a base
16. historically, soap was made from animal fat and ____.