Intro to Chemistry

Question 1

What is chemistry?

Answer 1

Study of the composition of matter and the changes it undergoes.

Question 2

Branches of chemistry

Answer 2

Physical, organic, inorganic, analytical, biochemistry.

Question 3

Physical chemistry

Answer 3

Study of the macroscopic and the atomic properties and phenomena in chemical systems.

Question 4

Organic chemistry

Answer 4

Study of carbon containing chemicals. It is found in most living organisms.

Question 5

Inorganic chemistry

Answer 5

Chemicals that do not in general contain carbon.

Question 6

Analytical chemistry

Answer 6

Study of the composition of matter. Focusing on separating, identifying and quantifying chemicals in matter.

Question 7

Biochemistry

Answer 7

Study of chemical processes that occur in living things.

Question 8

Scientific method

Answer 8

Ask a question, make observations, propose an explanation, make new observations.

Question 9

Theory

Answer 9

A broad explanation that is widely accepted. Explains why.

Question 10

Law

Answer 10

A statement that is always true. Does not explain why.

Question 11

Accuracy

Answer 11

How close a measurement is to the correct or accepted value.

Question 12

Precision

Answer 12

How close a series of measurements are to each other.

Question 13

Measurement Uncertainty

Answer 13

When it is not certain how much the measurement is. The smaller place it goes, the less uncertainty.

Question 14

Error

Answer 14

Experimental value - accepted value. Also known as uncertainty.

Question 15

Percent error

Answer 15

Absolute value of error/ accepted value *100.

Question 16

What is Matter?

Answer 16

Anything that has mass and volume. Either pure substances or mixtures.

Question 17

Mass

Answer 17

Amount of matter in a substance or object. SI(Kg)

Question 18

Volume

Answer 18

amount of space something takes up. SI(m^3)(L)

Question 19

Weight

Answer 19

The force of gravity on an object.

Question 20

Substances

Answer 20

Matter that has uniform and composition. Cannot be physically separated. Either elements or compounds.

Question 21

Compounds

Answer 21

A substance that has two or more elements chemically combined.

Question 22

Mixtures

Answer 22

Combination of substances that aren’t chemically combined. Can be physically separated.

Question 23

Heterogeneous mixture

Answer 23

Composition is not uniform.

Question 24

Homogeneous mixture

Answer 24

Composition is uniform.

Question 25

States of Matter

Answer 25

Solid, liquid, gas, plasma.

Question 26

Solids

Answer 26

-Definite shape
-Definite volume
-Particles vibrate around fixed axes

Question 27

Liquids

Answer 27

-Takes the shape of its container
-Definite volume
-Particles are free to move over each other, but are still attracted to each other

Question 28

Gases

Answer 28

-Takes shaped of its container
-No definite volume
-Particles move in random motion with little or no attraction to each other

Question 29

Plasma

Answer 29

Like a gas but particles are charged ions and free electrons. Conducts electricity and responds to magnetic fields

Question 30

Physical property

Answer 30

A characteristic of a substance that can be observed or measured without changing its identity. Intensive or extensive(depends on amount of matter).(color, hardness, malleability, solubility, electrical conductivity, density, melting points, boiling points)

Question 31

Chemical Property

Answer 31

Cannot be observed without changing the identity.

Question 32

Physical change

Answer 32

A change to matter where some properties change but not the identity. Can be reversible or irreversible.

Question 33

Chemical change

Answer 33

A change in matter which also changes its identity.

Question 34

Density

Answer 34

Density=Mass/Volume, how tightly material is packed together