S2

Question 1

What are homogeneous mixtures?

Answer 1

Homogeneous mixtures have parts that cannot be picked out.

Examples include sugar water and milk.

Question 2

What are physical properties?

Answer 2

Physical properties are characteristics that can be observed without changing the composition of a substance.

Examples include color, odor, texture, taste, freezing point, melting point, density, mass, and hardness.

Question 3

What are chemical properties?

Answer 3

Chemical properties indicate how a substance reacts with other substances and are only observed during a chemical change.

Examples include flammable, combustible, burnable, and ‘reacts with…’.

Question 4

What are physical changes?

Answer 4

Physical changes are alterations in form or appearance without changing the composition.

Examples include cutting, breaking, pulverizing, and changes in state such as melting, freezing, boiling, and subliming.

Question 5

What are chemical changes?

Answer 5

Chemical changes involve one or more substances reacting to form new substances with different chemical and physical properties.

Examples include rusting, burning, corrosion, digestion, respiration, and decaying.

Question 6

What is the Law of Conservation of Mass?

Answer 6

The Law of Conservation of Mass states that in any chemical or physical change, matter cannot be created or destroyed.

Mass of the Reactants = Mass of the Products.

Question 7

What is an example of the Law of Conservation of Mass?

Answer 7

An example is: Hydrogen + Oxygen → Water.

2 grams of hydrogen + 8 grams of oxygen = 10 grams of water.