Grade 10/ 11 Science Chapter 4 Review

ST

Chapter summaries

CHAPTER 4

Chapter summaries

C

hanges in matter

1 what are changes in matter?

• A physical change alters neither the nature nor the characteristic properties of matter. The atoms and molecules of the substance do not change (p. 108).

• A chemical change alters the nature and characteristic properties of matter. The bonds between atoms are rearranged, and new molecules are formed (p. 108).

• In a nuclear transformation, the particles making up an atomic nucleus are rearranged, and new elements are formed (p. 108).

2 CHEMICAL CHANGES

• Chemical changes are also called chemical reactions (p. 109).

• The law of conservation of mass states that the total mass of reactants is always equal to the total mass of products (p. 111).

• Balancing a chemical equation consists in placing a coefficient before each reactant and product so that the number of atoms of each element on the reactant side is equal to the number of atoms of each element on the product side (p. 111).

• Acid-base neutralization is a chemical change involving the reaction of an acid with a base, producing a salt and water (p. 119).

• Combustion is a form of oxidation that releases a large amount of energy (p. 122).

• Cellular respiration is a chemical change in which glucose and oxygen are used to generate energy. The reaction also produces carbon dioxide and water (p. 123).

• Photosynthesis is a chemical change that produces glucose and oxygen from solar energy, carbon dioxide and water (p. 124).