Science Exam Review

Question 1

How can matter be classified?

Answer 1

Into pure substances or input substances (mixtures)

Question 2

How can pure substances be classified?

Answer 2

By elements or compounds

Question 3

How can mixtures or impure substances be classified?

Answer 3

Homogeneous mixtures (you chat tell they’ve been mixed) or heterogeneous (and obvious mixture)

Question 4

How can elements be classified?

Answer 4

Metals, nonmetal, metaloids, noble gases

Question 5

Physical property:

Answer 5

Physical characteristics that are used to describe a substance or an object (when describing we use it senses)

Question 6

Physical change:

Answer 6

May change stage but doesn’t become a new substance and most are easy to reverse (includes melting, boiling, freezing, condensation, and sublimation

Question 7

Chemical change:

Answer 7

The original substance is changed into on or more different substances that have different properties (includes burning, cooking, and rusting)

Question 8

Chemical change:

Answer 8

Involve producing new substances and are difficult to reverse

Question 9

Some clues for a chemical change include:

Answer 9

New colour, heat or light is given off, a solid material (called a precipitate) forms in a liquid, bubbles of gas are formed, the change is difficult to reverse

Question 10

Chemical properties:

Answer 10

Seeing how suns stances (and objects) react with other things. Chemical properties tell us whether something is flammable or if it reacts with an acid or water.

Question 11

Some chemical properties include:

Answer 11

Combustibility, reaction with acid, & reaction with water

Question 12

Combustibility:

Answer 12

The ability of substances to react with oxygen to produce carbon dioxide, water and energy (alcohol & gas)

Question 13

Reaction with acid:

Answer 13

The ability of a substance to fact with acid. Proof includes bubbles and/or a colour change. (Limestone + acid & that produced has bubbles)

Question 14

Reaction with water:

Answer 14

the ability of a substance to react with water (sodium + water & that produces fumes and gas)

Question 15

What are he parts of an atom:

Answer 15

Neutrons & protons (in the nucleus) and electrons (circling the outside)

Question 16

Types of bonding:

Answer 16

Covalent & ionic

Question 17

Covalent bond:

Answer 17

One or more pairs of electrons are shared by two atoms

Question 18

Ionic bond:

Answer 18

one or more electrons from one atom are removed and attached to another

Question 19

Density:

Answer 19

Volume

Question 20

Volume

Answer 20

Density

Question 21

Mass

Answer 21

Volume x density

Question 22

Distance measured in space:

Answer 22

In astronomical units

Question 23

Solar eclipse;

Answer 23

Occurs when the moon passes between the sun and earth. The moon blocks (occults) the sun. (Can only happen at a new moon)

Question 24

Lunar eclipse:

Answer 24

Occurs when the moon passed freckly behind the earth into its shadow.

Question 25

Sunspots:

Answer 25

A spot appearing from time to time on the Suns surface, appears dark by contrast with its surroundings

Question 26

Flares:

Answer 26

A sudden rapid and intense variation in brightness

Question 27

Solar flares:

Answer 27

Occurs when magnetic energy that has built up in the solar atmosphere is suddenly released

Question 28

Big Bang theory:

Answer 28

An event filling all of pace with all particles of the universe rushing away from eachother

Question 29

Asteroid:

Answer 29

A small rocky body that orbits the sun

Question 30

Meteror

Answer 30

A small body of matter fork outer space that enters rather atmosphere and appears as a streak of light

Question 31

Meteoroid:

Answer 31

A small object moving in the solar sisters that would become a meteor of it enter earths atmosphere

Question 32

Meteorite:

Answer 32

A rocky meteor that survives is passage through the earths atmosphere and it hits the earth

Question 33

Comet:

Answer 33

A celestial object consisting of j e and dust. (When near the sun, a tail of gas and dust particles point away from the sun)

Question 34

Revolution of the earth:

Answer 34

The movement of the earth around the sun

Question 35

Rotation of the earth;

Answer 35

The eart turning on its own axis

Question 36

Humans in space:

Answer 36

Weightlessness, body fluid imbalance, muscular atrophy, space sickness