Science Chapter 3

Question 1

Define “chemical reaction”

Answer 1

A process by which two or more substances interact and produce different substances

I.e.molecules change through the rearrangement of their atoms

Question 2

Give an example of a chemical reaction

Answer 2

baking soda mixes with vinegar , producing carbon dioxide gas, water, and sodium acetate

NaHCO₃ (baking soda) + CH₃COOH (vinegar) →
CO₂ (carbon dioxide) + H₂O (water) + CH₃COONa (sodium acetate).

Question 3

Name 5 types of evidence of chemical reactions

Answer 3

color change
light formation
gas bubbles
precipitate
heat change

Question 4

What is the one way to be a sure a chemical reaction has occurred?

Answer 4

If a new substance is produced,
if the molecules change,
if the molecules rearrange

(these all mean the same thing in effect)

Question 5

Define reactant and product

Answer 5

reactant: on left, original substance

product: on right, converted substance