8th Grade

Question 1

Compounds

Answer 1

• made of two or more different atoms
• form ionic bonds(lose or gain electrons) and covalent bonds(share)
• chemical reaction

Question 2

Mixtures

Answer 2

-made of compounds and elements mixed together

Question 3

Colloids

Answer 3

Particles suspended

Question 4

Suspension

Answer 4

Particles fall to bottom

Question 5

Solute

Answer 5

Material that is dissolved

Question 6

Solvent

Answer 6

Liquid that does the dissolving

Question 7

Heterogeneous

Answer 7

Different throughout

Question 8

Homogeneous

Answer 8

Same throughout

Question 9

Physical change

Answer 9

Change in size, shape, or state

Question 10

Chemical change

Answer 10

Turns substance into a new substance

Question 11

Nuclear

Answer 11

Fusion(joining atoms nuclei)

-fission(splitting an atom)

Question 12

Physical property

Answer 12

Describes matter, appearance, observations with senses

-color, shape, texture

Question 13

Chemical property

Answer 13

Describes how easy matter can undergo a chemical change

-flammable, combustion

Question 14

Who first created the periodic table?

Answer 14

Mendeleev

• was arranged by atomic mass
• later was rearranged by Henry Moseley (arranged by atomic number)

Question 15

Period

Answer 15

Row, number of energy levels in electron cloud

Question 16

Group

Answer 16

Column, grouped by families with like properties

Question 17

Common groups

Answer 17

Alkali metals, alkaline earth metals, transition metals, halogens, and noble gases

Question 18

What are the steps to the scientific method?

Answer 18

1. Question/problem
2. Research
3. Hypothesis
4. Experiment
5. Analyze data
6. Conclusion
7. Communication

Question 19

Control

Answer 19

What you’re comparing everything to

Question 20

Independent variable

Answer 20

You control, the one that changes

-always in the x axis

Question 21

Dependent variable

Answer 21

What happens, the results

-always on the y axis

Question 22

Scientific conversion

Answer 22

Kilo-1000
Hecto-100
Deca-10
Base-1(meter, liter, gram)
Deci-1/10
Centi-1/100
Milli-1/1000
•remember: King Henry Died By Drinking Chocolate Milk

Question 23

Area

Answer 23

A=L•W

-centimeters squared

Question 24

What is the unit for length?

Answer 24

Centimeters

Question 25

Volume

Answer 25

V=L•W•H | -centimeters cubed or milliliters

Question 26

What is absolute zero and boiling/freezing points of water?

Answer 26

- Absolute zero: 0K or -273°C - Boiling: 212°F or 100°C - Freezing: 32°F or 0°C

Question 27

What do you use to measure mass?

Answer 27

Triple beam balance | -measured in grams

Question 28

What is weight measured in?

Answer 28

Newtons (spring scale) or water displacement (milliliters)

Question 29

Force =?

Answer 29

F=M•A | -measured in newtons

Question 30

Density =?

Answer 30

D=M/V | -measured in g/mL or g/cm^3

Question 31

Energy

Answer 31

The ability to do work

Question 32

What are the uses for sound?

Answer 32

Ultrasounds and sonar sounds

Question 33

Frequency

Answer 33

Need of waves in a certain amount of time, determines pitch

Question 34

Amplitude

Answer 34

Height of wave, determines loudness

Question 35

Interference

Answer 35

Sound waves overlap

Question 36

Temperature

Answer 36

Atom movement(average kinetic energy)

Question 37

Absolute zero

Answer 37

Coldest temperature possible, no atom movement

Question 38

Conduction

Answer 38

Direct contact

Question 39

Convection

Answer 39

Travels in currents

Question 40

Radiation

Answer 40

Travels in waves

Question 41

Law of conservation of energy

Answer 41

Energy can't be created or destroyed, only transferred

Question 42

Speed

Answer 42

Speed= distance/time

Question 43

Velocity

Answer 43

Speed and direction

Question 44

Acceleration

Answer 44

A change in velocity

Question 45

What are the six forms of energy?

Answer 45

``` Mechanical Electromagnet Chemical Thermal Nuclear Electrical ```

Question 46

What is the behavior of light?

Answer 46

- Reflects: bounces off - Refracts: bends - Interference: light waves cancel each other out - Diffraction: light bends around barrier and spreads out - Convex: vexes out - Concave:caves in

Question 47

What are newtons three laws?

Answer 47

1. Law of Inertia: an object in motion will stay in motion and an object at rest will stay at rest unless acted on by an outside force 2. Force=mass•acceleration 3. For every action there is an equal and opposite reaction

Question 48

Force

Answer 48

A push or pull (gravity, friction, nuclear)

Question 49

Work

Answer 49

Transfer of force over a distance and must have motion (Work=force•distance)

Question 50

Power

Answer 50

Work done in a period of time (Power=work/time) | -units: watts

Question 51

What are the six simple machines?

Answer 51

Lever, pulley, wheel and axle, wedge, screw, inclined plane

Question 52

Elements

Answer 52

- made up of same atoms | - arranged on periodic table by the number of protons