Ch 1 - What is Chemistry?

Question 0

Science

Answer 0

The experimental investigation and explanation of natural phenomena; knowledge from experience

Question 1

How are science and technology changing?

Answer 1

Change is accelerating: 100 years from now will be more different from today than today is from 500 years ago.

Question 2

Technology

Answer 2

The application of scientific knowledge; the use of knowledge in practical applications

Question 3

Is science always right?

Answer 3

No, it is a human endeavor

Question 4

Is technology always good?

Answer 4

No, it is driven by human desires (the atomic bomb, etc)

Question 5

Chemistry

Answer 5

The study of matter and the transformation(s) it undergoes; “central science”; a bridge between physics and biology

Question 6

Matter

Answer 6

Anything that has mass and occupies space; “stuff”

Question 7

Transformation

Answer 7

Changes in matter

Question 8

Pure substance

Answer 8

Only a single type of matter (table salt, table sugar/sucrose)

Question 9

Mixture

Answer 9

2+ substances intermixed (mixture of salt and sugar, rocks); can be separated by physical means

Question 10

Elemental substance

Answer 10

A pure substance made of only one type of atom (pure gold Au, oxygen in the air O2)

Question 11

Compound

Answer 11

A pure substance made of 2+ different elements in a fixed ratio (H2O)

Question 12

Homogeneous mixture

Answer 12

A mixture with a uniform composition (brass, sugar dissolved in water)

Question 13

Heterogeneous mixture

Answer 13

A mixture without a uniform composition (oil and water, sugar and salt mixed together)

Question 14

Element

Answer 14

The basic building block of all matter; periodic table of elements; ~119 known (90 natural, 23 synthetic)

Question 15

Who first proposed the atomic theory?

Answer 15

Democritus in ~400 BC theorized the smaller unit if all matter was called an atom

Question 16

Who disagreed with the atomic theory?

Answer 16

Aristotle ~400 BC proposed a continuous model suggesting that there was no limit to how small something could go. This theory won out for over 2000 years.

Question 17

Atoms

Answer 17

The smallest complete unit if am element

Question 18

Chemical formula

Answer 18

The number if each type of atom that makes up the smallest unit of the compound

Question 19

Physical transformation

Answer 19

The same substance, but a different state of matter

Question 20

States of matter

Answer 20

Solid, liquid, gas

Question 21

Characteristics of a solid

Answer 21

Has a definite shape and volume

Question 22

Characteristics of a liquid

Answer 22

Has a definite volume, but no definite shape

Question 23

Characteristics of a gas

Answer 23

Has neither definite volume or definite shape

Question 24

Physical properties

Answer 24

Those properties of a substance that can be observed without changing the substance.

Question 25

Examples of physical properties

Answer 25

Color. Mass. Weight. Scent. Hardness. Boiling point. Melting point. Density.

Question 26

Physical change

Answer 26

A change in which the chemical identity if the substance is not changed. (Melting, freezing, reshaping)

Question 27

Freezing

Answer 27

A substance changing from a liquid state of matter to a solid state of matter

Question 28

Melting

Answer 28

A substance changing from a solid state of matter to a liquid state of matter

Question 29

Vaporization

Answer 29

A substance changing from a liquid state of matter to a gaseous state of matter

Question 30

Condensation

Answer 30

A substance changing from a gaseous state of matter to a liquid state of matter

Question 31

Sublimation

Answer 31

A substance changing from a solid state of matter directly to a gaseous state of matter

Question 32

Chemical properties

Answer 32

Those properties of a substance that can only be studied by forming new substances; describes how a substance reacts

Question 33

Examples if chemical properties/changes

Answer 33

Rusting. Burning. Tarnishing. Exploding. Toxicity. Inert (does not react with anything).

Question 34

Chemical changes

Answer 34

Changes in being the chemical identity of a substance is changed; when a substance changes to a different substance(s); described when substances undergo a chemical change.

Question 35

Chemical reaction

Answer 35

Describes a chemical transformation

Question 36

Reactants

Answer 36

The starting substances in a chemical reaction

Question 37

Products

Answer 37

The newly formed substances following a chemical reaction

Question 38

5 characteristics of science

Answer 38

1) Testable 2) Reproducible 3) Explanatory 4) Predictive 5) Tentative

Question 39

Scientific method

Answer 39

1) Experiment 2) Law 3) Theory 4) Model Observation --> Hypothesis --> Experiments --> Theory

Question 40

Experiment

Answer 40

Observations and data

Question 41

Law

Answer 41

Concise summary of outcome(s)

Question 42

Theory

Answer 42

Attempt to explain why a law exists; a set of tested hypotheses that explain natural phenomena; best current explanation; always tentative and may change as observations continue/change

Question 43

Model

Answer 43

A physical picture or mathematical expression of a theory; tangible items/pictures used to represent invisible processes; helps to apply, understand, and visualize a theories; always incomplete and simplified --> limited

Question 44

Scientific hypothesis

Answer 44

Testable explanations of observed data; tested by designing and performing experiments

Question 45

Relationship between a theory and a law

Answer 45

A theory attempts to explain why a least is correct

Question 46

Relationship between a law and experimental data

Answer 46

A law is a summary of experimental results

Question 47

Limitations to the scientific method

Answer 47

1) Sample size 2) Shows avg behavior of the group 3) Bias 4) Science is limited to studying that which is observable as well as processes in which variables can be controlled

Question 48

Bias

Answer 48

Stein preference or inclination that inhibits impartial judgement

Question 49

Molecule

Answer 49

A group of 2+ atoms held together by chemical bonds

Question 50

Molecular model

Answer 50

3D representations of molecules (a diamond)