MODULE 1

Question 1

Chemistry is the central science because ______________.

Answer 1

it affects a lot of fields.

Question 2

Steps under Scientific Method

Answer 2

1. Think of an idea
2. Plan your experiment.
3. Research your topic.
4. Experiment.
5. Collect and record data.
6. Come to a conclusion.

Question 3

These are guesses that can be tested by experimentation.

Answer 3

Scientific Hypotheses

Question 4

These are useful for predictive value and can be modified or discarded.

Answer 4

Scientific Theories

Question 5

These are data summarized in brief statements.

Answer 5

Scientific Laws

Question 6

These use pictures for invisible processes to give way for easier visualization.

Answer 6

Scientific Models

Question 7

These are examples of scientific models

Answer 7

Newton’s Law of Inertia
Einstein’s Special Theory of Relativity

Question 8

Deals with the study of Matter, all in terms of composition, structure, properties, transformations, and energy involved in such transformations.

Answer 8

Chemistry

Question 9

Matter

Answer 9

anything that occupies and has mass; material of the universe

Question 10

Mass

Answer 10

measures the quantity of matter

Question 11

Weight

Answer 11

gravitational force of attraction exerted by the Earth on a body

Question 12

What are the five physical states of matter?

Answer 12

1. Solid
2. Liquid
3. Gas
4. Plasma
5. Bose-Einstein Condensate

Question 13

Solid

Answer 13

incompressible and has definite shape and volume

Question 14

Liquid

Answer 14

indefinite shape but definite volume and is incompressible

Question 15

Gas

Answer 15

indefinite shape and volume

Question 16

Plasma

Answer 16

consists of highly-charged particles with extremely high kinetic energy/ion-charged gases (stars, interior of the sun, neon signs from ionised noble gases, etc.)

Question 17

Bose-EInstein Condensate

Answer 17

has properties of a superfluid (fluid that flows without friction); almost no kinetic energy; evident in Rubidium which are clumps of atoms behaving as a single atom.

Question 18

What are the two properties of matter?

Answer 18

1. Intrinsic
2. Extrinsic

Question 19

Intrinsic Properties

Answer 19

Independent of the amount of material

Question 20

Extrinsic Properties

Answer 20

Dependent on the amount of material

Question 21

Physical Properties

Answer 21

measured without changing the basic identity of the substance (e.g. colour, density, odour, melting point)

Question 22

Chemical Properties

Answer 22

describe how substances react or change to form different substances (e.g. hydrogen burns in oxygen)

Question 23

Physical Changes

Answer 23

no change in the composition of matter, only physical appearance changes

Question 24

What are examples of physical changes?

Answer 24

1. Changes of state/phase (e.g. melting, evaporation, sublimation, freezing, condensation, deposition)
2. Dissolving solute in solvents (e.g. table salt or sugar or sodium chloride in water; INTERACTED, not reacted)

Question 25

Changes from one physical state to another involves _______________.

Answer 25

Absorption/release of energy

Question 26

Gas has the highest Kinetic Energy because it _______________.

Answer 26

moves around constantly, meaning it takes in energy (+).

Question 27

Solid has the lowest Kinetic Energy because ________________.

Answer 27

It is compact, meaning a transition to a solid state indicates a release of energy (-).

Question 28

Because there is an absorption of energy, a substance is cold to the touch. What is this property called?

Answer 28

Endothermic

Question 29

Because there is a release in energy, a substance is hot to the touch. What is this property called?

Answer 29

Exothermic

Question 30

Chemical Changes

Answer 30

change in the composition of matter; both intrinsic and extrinsic properties are changed; represented by a chemical reaction

Question 31

This can be described by chemical equations

Answer 31

Chemical Reactions

Question 32

These are examples of chemical reactions

Answer 32

1. When pure hydrogen and pure oxygen react completely, they form pure water. In the flask containing water, there is no oxygen or hydrogen left over. 2. When iron reacts with oxygen in the presence of warer or air moisture, a new substance is formed, commonly called rust.

Question 33

What are the two classifications of matter?

Answer 33

1. Pure Substances 2. Mixtures

Question 34

Pure Substance

Answer 34

definite composition and properties

Question 35

simplest type of matter, cannot be decomposed into simpler substances via chemical reactions. It can be found in the Periodic Table and can have a symbol.

Answer 35

Elements

Question 36

combination of elements in a definite ratio by mass, can be decomposed into the constituent elements.

Answer 36

Compounds

Question 37

formed by covalent bonding of the component atoms; could be a compound (H2O) or one type of element like diatomic gases (O2)

Answer 37

Molecules

Question 38

Allotropes

Answer 38

some elements exist in different forms (e.g. carbon - diamond, graphite, graphene, etc.; oxygen - O2, 03; phosphorus - red, white, black, and purple)

Question 39

Heterogeneous mixtures

Answer 39

made up of two/more phases; indefinite composition and properties

Question 40

Homogeneous mixtures

Answer 40

one phase only; definite composition and properties

Question 41

Colloids

Answer 41

intermediate phase (1-100 nm)

Question 42

Solutions

Answer 42

homogeneous; one phase, usually prepared with definite proportions of solute (the dissolved component) and solvent (the dissolving component in larger amount)

Question 43

Suspensions

Answer 43

heterogeneous; separate into layers/phases over time; can separate particles via filtration

Question 44

Colloids

Answer 44

mixtures with particle size (1-1000 nm), intermediate between that of solutions and suspensions, do not separate into layers and cannot be filtered; can scatter light

Question 45

light scattering by particles in a colloid/very fine suspension; also known as Willis-Tyndall scattering.

Answer 45

Tyndall Effect