Chapter 1

Question 1

What is Chemistry?

Answer 1

It is the study of properties and behavior of matter.

Question 2

What is matter?

Answer 2

Matter is anything that has mass and takes up space.

Question 3

The properties of atoms and molecules…

Answer 3

…Distinguish one type of matter from the other.

Question 4

Atoms

Answer 4

Are submicroscopic particles that are the fundamental building blocks of ordinary matter. Free atoms are rare in nature; more commonly they bind together in specific arrangements to form a molecule.

Question 5

The 116 different types of atoms are called…

Answer 5

Elements

Question 6

Classification of matter depends on…

Answer 6

…its state and composition.

Question 7

Solid

Answer 7

Has a fixed shape and volume; may be crystalline (organized in patterns with long-range) or amorphous (no long-range order)

Question 8

Liquid

Answer 8

Fixed volume but no fixed shape. Atoms are as closely bound as solid matter, but they are more free to move. They tend to assume the shape of their container.

Question 9

Gas

Answer 9

Neither its volume or shape are fixed. Sample take these properties from the gas’ container.

Question 10

Increasing of temperature leads to a…

Answer 10

…change in the state of matter.

Question 11

Pure substances vs. Mixture

Answer 11

If a certain type of matter has uniformity throughout its composition, then it is called homogeneous. Homogeneous substances can have a variable composition, being called homogeneous mixtures or if they don’t, they are called pure substances. Pure substances can be separated into simpler substances and are called compounds, or are not breakable into smaller substances are called elements. Now, if it is not uniform, matter is classified as heterogeneous.

Question 12

Heterogeneous vs Homogeneous

Answer 12

Heterogeneous mixtures do not have an uniform composition of particles and will often separate into its constituent parts; homogeneous mixtures have a uniform composition of constituent particles down to a microscopic level and do not separate into its constituent parts. Basically, if there is no difference on the molecular level, then it is homogeneous. If the difference is more on the cellular level, then it’s heterogeneous.

Question 13

What are the three main processes for separating mixtures?

Answer 13

Decanting, distillation, and filtration.

Question 14

Physical changes

Answer 14

They only alter the state and appearance of the matter, but not is composition, which means that the atoms and molecules do not change. It results in a different form of the same substance. Some examples are: odor, taste, color, appearance, melting point, boiling point.

Question 15

Chemical changes

Answer 15

Leads to atoms getting rearranged, transforming that substance into something different. Some examples are: Acidity, toxicity, flammability, corrosiveness, etc.

Question 16

Physical and chemical changes are…

Answer 16

…representations of physical and chemical properties.

Question 17

Properties of a compound are always the same properties of its elements.

Answer 17

False. The properties of a compound can differ greatly from the properties of the elements that are part of it.

Question 18

It states that a sample of pure matter will always have the same elemental composition, regarding of its source.

Answer 18

Law of Constant Composition or Law of Definite Composition

Question 19

Intensive properties

Answer 19

Do not depend on the amount of the substance, such as temperature, color, and density. Also called qualitative, help identifying such substances.

Question 20

Extensive properties

Answer 20

Depend on the amount of substance. These include mass, weight, and volume. They are also called quantitative.

Question 21

Energy

Answer 21

Capacity to do work

Question 22

Work

Answer 22

The action of a force through distance

Question 23

Kinetic energy

Answer 23

Regarding a certain object’s motion

Question 24

Potential energy

Answer 24

Energy associated with a certain object’s position or composition. Usually objects with a high rate of potential energy tend to be unstable.

Question 25

Thermal energy

Answer 25

Associated with the temperature of an object. It is considered a type of kinetic energy because it arises from the motion of individual atoms or molecules.

Question 26

Mass

Answer 26

Kilogram (Kg)

Question 27

Length

Answer 27

Meter (m)

Question 28

Second (s)

Answer 28

Time

Question 29

Kelvin (K)

Answer 29

Temperature

Question 30

Amount of substance

Answer 30

Mole (mol)

Question 31

Ampere (A)

Answer 31

Electric current

Question 32

Candela (Cd)

Answer 32

Luminous intensity

Question 33

All the temperature scales are called absolute scales

Answer 33

False. Only the Kelvin scale is also known as the absolute scale, as it is the only one that does not allow negative temperatures.

Question 34

Absolute zero is…

Answer 34

…the temperature at which molecular motion virtually stops.

Question 35

Mass vs. weight

Answer 35

Mass is the quantity of matter within it, while the weight is the measure of the gravitational pull on a certain object’s matter.

Question 36

Derived units

Answer 36

Combination of other units in order to create a new one.

Question 37

Precision vs. Accuracy

Answer 37

Precision is how well repeated measurements agree with each other, while accuracy is how well measurement agree with the correct value.

Question 38

Potential energy decreases

Answer 38

as kinetic energy increases

Question 39

Law of Conservation of Energy

Answer 39

States that energy is nor created or destroyed

Question 40

Systems with high potential energy tend to change in a direction…

Answer 40

…That lowers their potential energy, releasing it into the surroundings.