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Grade 8 > Science 8 Review > Flashcards

Science 8 Review Flashcards

1
Q

What is static electricity?

A

non-flowing charges; imbalance between positive(+) and negative (-) charges.

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2
Q

What are the types of charging?

A

friction, conduction, induction

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3
Q

What is friction?

A

rubbing together of surfaces that result in electron transfer

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4
Q

What is conduction?

A

flowing of electrons from one surface to another through DIRECT CONTACT

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5
Q

What is Induction in static electricity?

A

Rearrangement of charges WITHOUT CONTACT

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6
Q

What is an atom and what are its parts?

A

atom- the smallest unit of matter

parts- electrons, protons and neutrons

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7
Q

What causes lightning?

A

caused by imbalances of charges between the clouds & other things (can be buildings, trees, etc.)

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8
Q

Why does lightning usually occur during storms?

A

because the heat convection in the clouds constantly change the temperature within the cloud, disturbing the placement of charges

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9
Q

Describe electric current.

A

electric current is the RATE OF FLOW OF CHARGES

P.S.- electric current & charge are directly proportional

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10
Q

What are the components/ PARTS of a circuit?

A

Energy source/ battery, switch, connecting wires & load/resistor

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11
Q

What are the QUANTITIES of a circuit?

A

Resistance, Voltage, Power & Current

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12
Q

What is a current?

A

rate of flow of charges

formula: charge/time
unit: Amperes

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13
Q

What is Voltage?

A

the force that generates current

formula: Current x Resistance
unit: Volts

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14
Q

What is Resistance?

A

resists the flow of charges, increases with the length of the connecting wires

formula: Voltage/Current
unit: Ohms

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15
Q

What is Power (in electric current)?

A

Heat generated by electricity

formula: voltage x current
units: Watts

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16
Q

Ohms’ Law

A

voltage & current are directly proportional, while voltage & resistance are indirectly proportional

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17
Q

types of circuits

A

Series circuit & parallel circuit

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18
Q

describe a series circuit (with advantages & disadvantages)

A
  • has only a single path for current flow (ex: Christmas tree lights)
  • A: simple design, long battery life & less likely to overheat, since it draws out less energy from the battery
  • DA: of one load breaks, the others will break as well
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19
Q

Describe a parallel circuit (with advantages & disadvantages)

A
  • each load has its own separate path of current flow (ex: room lights)
  • A: independent control over the bulbs & the bulbs are brighter compared to those in the series circuit
  • DA: likely to overheat; draws out more energy from battery
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20
Q

Concept Checking: will (-) and (-) attract or repel? Why?

A

Repel, because only opposite charged objects attract.

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21
Q

Concept Checking: In electricity, which part of an atom is the one being transferred?

A

Electrons.

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22
Q

Concept Checking: When an atom has 8 protons, 5 neutrons and 5 electrons, what is its charge?

A

Positively charged, since there are more protons.

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23
Q

Concept Checking: Why don’t Birds & Squirrels get electrocuted on power lines?

A

Electricity is always looking for a way to travel to the ground. However, the birds & squirrels aren’t in any contact with the ground since they’re on the power lines. Plus, the feet/ claws (?idk) of the birds have some sort of insulator on them.

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24
Q

describe a plate.

A

massive slab of rock(continental/ oceanic)

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25
Q

describe a fault.

A

crack in earth’s crust; where rocks move across each other

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26
Q

describe stress (in earthquakes)

A

force that causes the faults to move

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27
Q

What are the 3 general plate movements?

A

Convergence (Continental-Continental, Continental-Oceanic, Oceanic-Oceanic), Divergent, Transform

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28
Q

C-C Convergence plate movement

A

forms mountain ranges & earthquakes

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29
Q

C-O Convergence plate movement forms what?

A

forms mountain ranges, volcanoes (thru subduction) & earthquakes

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30
Q

What is subduction?

A

when the oceanic plate goes under the continental plate (because it’s denser), melts and would look for a way to release the heat= volcanoes

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31
Q

O-O convergence plate movement

A

forms underwater volcanoes & trenches

32
Q

Divergent plate movement result in…?

A

drifting apart of plates, forms volcanoes, rivers, underwater volcanoes & earthquakes, rift valleys & ridges

33
Q

Transform plate movement causes what?

A

earthquakes & abandoned rivers

34
Q

What causes plate movements?

A

mantle convection current

35
Q

Earthquakes are usually @ plate boundaries. But why is it that not all boundaries have volcanoes?

A

Because not all boundaries have oceanic-continental convergence. Some might be continental-continental convergence

36
Q

Why are plate boundaries called faults but not all faults are plate boundaries?

A

Because not all cracks in the earth’s crust are the boundaries of a plate.

37
Q

describe a fault.

A

fracture/zone of fractures between 2 rocks

38
Q

types of faults

A

normal, reverse/ thrust & transform/ strike-slip

39
Q

Normal Fault

A

caused by tensional stress (divergent plate movement)

hanging wall slides down

40
Q

Reverse/ Thrust Fault

A

caused by compressional stress (convergence plate movement)

hanging wall moves upward

41
Q

describe a Transform/ Strike-Slip Fault

A

plates slide past each other

most damaging since 2 plates are moving

42
Q

What is the Western Philippine Fault often referred to as? (Hint: it’s in the Metro Manila region)

A

“The Big One”

This is because it is a very active fault and this is the reason we have an annual earthquake drill.

43
Q

Where do earthquakes usually occur in?

A

the Circum-Pacific belt, Mid-Atlantic Ridge & the Alpide belt

44
Q

Why do we usually experience earthquakes here in the Philippines?

A

b/c we’re in the Ring of Fire, where there are a ton of active volcanoes

45
Q

What are the 3 causes of earthquakes?

A

volcanic activity, tectonic plate movement & man-made activity

46
Q

what are some effects of earthquakes?

A

landslide, avalanche, tsunamis, new landforms, underground water reservoirs, spring, minerals& oil

47
Q

what are the 3 types of earthquakes?

A

volcanic, tectonic, collapse & explosion

48
Q

How do earthquakes occur?

A

plates slowly move, compression increases, rocks break apart @ fault lines, energy is released as seismic waves & earth’s surface vibrates

49
Q

Which part of an earthquake refers to a fracture in the crust?

A

fault

50
Q

which part of an earthquakes refers to where the most energy is released& is the origin of the earthquake

A

focus

51
Q

which part of the earthquake is directly above the focus?

A

epicenter

52
Q

describe a fault scrap

A

slope caused by the displacement of rock/crust

53
Q

describe seismic waves/ wave front (as a part of an earthquake)

A

transmit energy released by the earthquake

54
Q

types of Seismic waves

A 
Body waves (interior of earth, travels faster)
Surface waves- 2-3 km, damages stuff
55
Q

P–waves (primary)

A
  • a body wave
  • fastest (4-7 km)
  • compression type
56
Q

describe S-waves (secondary)

A
  • a body wave
  • 2-5 km
  • transverse shear wave
57
Q

L-waves (love waves)

A
  • a surface wave (slowest kind of wave& most damage)
  • 2-3 km
  • moves side 2 side
58
Q

R-waves (Rayleigh)

A
  • a surface wave (slowest kind of wave& most damage)

- rolling wave movement

59
Q

Intensity V.S. Magnitude

A

Intensity- strength perceived by humans, measured thru its effect
Magnitude- energy released by earthquake @ its focus, measured by seismograph

60
Q

Concept Checking: can earthquakes be predicted?

A

no.

61
Q

Concept Checking: Is tectonic plate movement the only cause of an earthquake?

A

no, there is also volcanic activity & man-made activities

62
Q

Concept Checking: earthquakes only happen on hot season

A

no, they can happen any time.q

63
Q

REVIEW: Describe how air convection works.

A

cold air goes down= High Pressure Area (HPA)

hot air goes up= Low Pressure Area (LPA)

64
Q

Describe Land Breeze and Sea Breeze

A

Land breeze- nighttime, cold air from land to sea

Sea Breeze- day time, cold air from sea to land

65
Q

What is the difference of Typhoon, Hurricane and Cyclone?

A

Typhoon-@NW Pacific, counterclockwise movement
Hurricane-NE Pacific & Atlantic, counterclockwise movement
Cyclone- @South Pacific Ocean& Indian Ocean, clockwise movement

66
Q

How are Typhoons formed?

A
  1. Warm moist air moves over the ocean
  2. Water vapor rises into the atmosphere
  3. water vapor cools & condenses into liquid as it rises
  4. Condensation releases heat into the atmosphere making the air lighter
  5. warmed air continues to rise w/ moist air from the ocean taking its place & making more wind
67
Q

Tropical Cyclogenesis

A
  1. water evaporates, comes into contact w/ cold air=clouds
  2. column of low pressure develops @ the center & winds form around the column
  3. pressure in the center weakens, speed around the wind increases
68
Q

Stage 1 of the Development of a typhoon

A
  • tropical disturbance
  • LPA
  • thunderstorm, clouds & showers
69
Q

Stage 2 of the Development of a typhoon

A
  • tropical depression (signal 1)
  • more organized thunderstorms& circulation of air
  • wind speeds of 38 mph
70
Q

Stage 3 of the Development of a typhoon

A
  • tropical storm (signal 2&3)
  • receives an official name (when it’s 39 mph+)
  • has recognizable pattern of rotation
71
Q

Stage 4 of the Development of a typhoon

A
  • typhoon/hurricane/cyclone (signal 4&5)
  • has more energy (at least 74 mph)
  • has a visible eye in satellite images
  • super typhoon: greater than 115 mph
72
Q

Factors that strengthen typhoons

A
  • sea surface temp of 26.5 degrees Celsius
  • warm moist air
  • ocean area
73
Q

Factors that weaken typhoons

A
  • temp less than 26.5 degrees Celsius
  • dry air
  • land masses (mountain ranges…)
74
Q

What is a landfall?

A

when a typhoon weakens due to encounters with land masses

75
Q

Why do typhoons move in a curved path?

A

Because of wind patterns on earth

76
Q

Why are we prone to typhoons here in the Philippines?

A

Because we are in the Southeast Asian Sea, bordered by the Pacific Ocean (warm,humid temp. & big bodies of water around us)

77
Q

Parts of the typhoon

A

Eye-area w/ the lowest pressure; the center
Eye wall- innermost ring of convection; has the strongest winds& rain
Rain Bands-clouds that spin outside the wall (not so rainy)

Grade 8 (6 decks)

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