Chapter 3: Matter and Energy

Question 1

Define Matter

Answer 1

Matter is any substance that has mass and takes up space

Question 2

Describe the difference between the three physical states of matter: gas, liquid, and solid based on relative intermolecular attraction and motion.

Answer 2

There is no intermolecular attraction in gases. There is varied strength in liquids (based on particles present). There is very strong intermolecular attraction in solids. Lots of motion in gases. liquids have motion. There is very little motion in solids

Question 3

For each physical state of matter, describe its characteristic properties of shape and volume.

Answer 3

Gases indefinite shape and volume. Liquids have indefinite shape and definite volume. Solids have definite shape and volume.

Question 4

Distinguish between an atom, an element and a compound.

Answer 4

Atoms are the smallest unit of an element that have properties of an element. Elements are made up of one kind of atom and cannot be broken down into something similar. Compounds are chemical combination of elements, the elements are fixed in a whole number ratio

Question 5

Describe the difference between a pure substance and a mixture.

Answer 5

A pure substance has constant composition can be an element or a compound. A mixture is composed of two or more substances

Question 6

Tell what method is used to separate components of a compound.

Answer 6

To separate a compound, it needs to be separated by chemical methods

Question 7

Distinguish between a homogeneous mixture and a heterogeneous mixture.

Answer 7

Homogenous mixtures have uniform composition throughout the mixture. Heterogenous mixture have different composition throughout the mixture

Question 8

List one physical method used to separate the components of a mixture.

Answer 8

A method used to separate a mixture is filtration.

Question 9

Define the physical properties of matter.

Answer 9

Physical properties include all physical characteristics of matter, Quantitative properties include temp. length, volume, density. Qualitative properties include color, texture, physical state, taste.

Question 10

Define the chemical properties of matter

Answer 10

Chemical reactions that do or do not occur

Question 11

Describe physical change

Answer 11

Physical change is when the appearance changes but the composition does not.

Question 12

Define chemical change

Answer 12

Chemical change because of chemical reactions that produce something new, that was not previously present

Question 13

Identify examples of change as either physical change or chemical change.

Answer 13

Physical changes are changes in shape, temperature or texture. Examples of hemical changes are rusting, buring or rotting

Question 14

List three different observations that are evidence of a chemical change.

Answer 14

Evidence of chemical change is formation of gas, a change in heat either cooler or hotter, or a permanent color change

Question 15

List the law of conservation of mass

Answer 15

The mass of the product equals the mass of the reactants

Question 16

Distinguish between potential energy and kinetic energy

Answer 16

Potential energy is stored energy. Kinetic energy is energy at work.

Question 17

List the two common units used to measure energy

Answer 17

The two measurements of energy is calories and joules

Question 18

List the law of conservation of energy

Answer 18

Energy is not created or destroyed, it is rearranged

Question 19

Distinguish between an exothermic physical change and an endothermic physical change.

Answer 19

An exothermic physical change is when a subtance becomes colder. And endothermic physical change is when a subtance becomes warmer.

Question 20

Distinguish between an exothermic reaction and an endothermic reaction

Answer 20

Exothermic reactions are when heat is released, making environment warmer. Endothermic reactions are when heat is absorbed making the environment cooler.

Question 21

Remember the conversion between Celsius and Kelvin

Answer 21

Temperature in Celsius plus 273 = Temperature in Kelvin