8th grade science

acceleration

force / mass

force

mass * acceleration

mid ocean ridge

in the ocean moving apart

rift valley

on land moving apart

mountain

on land with one plate sliding under

trench

in the ocean with one plate sliding under

neap tide

L shape with the highs and lows close

spring tide

Sun moon and earth in a line kind of the highs and lows are far apart

acid

Ph below 7

alkaline

ph is 7

base

ph above 7

summer in the southern hemisphere
winter in the northern hemisphere

the top of earth is tilted away from the sun

Winter in the southern hemisphere
summer in the northern hemisphere

top of the earth is tilted towards the sun

Adaptation

the process by which a population becomes better suited to its environment through natural selection.

Adaptations

traits that increase organisms' fitness (the ability to survive and reproduce in a particular environment).

Structural adaptations

physical features

Behavioral adaptations

actions

Physiological adaptations

internal body processes

Trait Variations

Individuals in a population with small differences inherited from their parents

Organisms fitness

ability to survive and reproduce in its environment.

Advatageous traits

Traits that increase fitness

Disadvantageous traits

Traits that decrease fitness

Natural selection

the process by which advantageous inherited traits become more common (and disadvantageous traits become less common) in a population over generations.

genes

segments of DNA molecules that determine an organism's inherited traits

Protein

molecules that carry out many different functions in cells. functions include providing structure and carrying out chemical reactions.

Amino acids

Proteins are made up of smaller parts called what

traits

features of an organism that we can observe. All organisms inherit these features from their parents.

Genes

Information about inherited traits is found in what? what tells cells which molecules to make and when to make them.

Chromosomes

Genes are part of structures called what in the nucleus of multicellular organisms

Cells

what is the smallest unit that can carry out all of the functions of life

micrograph

a photograph of real cells taken with the help of a microscope

Cell membrane

the barrier that surrounds the cell and controls what enters and leaves.

cytoplasm

the jelly-like fluid that fills the cell and contains all of the cell's internal parts

Cytoplasm and the cell membrane

what gives structure to the cell.

Mitochondria

organelles that break down nutrients to produce energy for the cell

Nucleus

stores the cell's DNA molecules that hold instructions that the ribosomes use to build proteins.

plant cells

a cell with a cell wall and chloroplasts

chloroplasts

capture sunlight to make food for the plant through photosynthesis.

the cell wall

strong outer layer that provides support and protection.

Vacuoles

storage structures in cells

Stability

how well an ecosystem can recover after a disruption.

Sustainability

the ability of an ecosystem to keep functioning over time—even through disruptions—and provide the resources that organisms need to survive.

Stability and sustainability of an ecosystem

The health and survival of organisms depend on what

Biodiversity

the variety of species in an ecosystem.

Extinction

what happens when organisms can no longer survive because of changes to their ecosystems.

ecological succession.

Ecosystems recover from disruptions through what

secondary succession

what occurs after a disruption in an existing ecosystem.

Primary succession

what happens in new or newly exposed environments

Biotic

Living part of an ecosystem

Abiotic

Nonliving part of an ecosystem

Climate change

warmer temperatures and shifts in weather patterns

Deforestation

when people cut down forests to clear land.

Overfishing

when people catch fish faster than the population can recover

Pollution

adds harmful substances to the air, water, or soil.

Carbon Cycle

what includes four main processes: photosynthesis, respiration, decomposition, and combustion.

carbon source

any process that adds carbon to the atmosphere,

carbon sink

removes carbon from the atmosphere.

Burning fossil fuels

largest source of greenhouse gas emissions from human activities

Weather

the state of the atmosphere at a specific time and place.

Climate

is the long-term weather pattern in a specific area.

tropical cyclone

rotating storm with a low-pressure center that forms over warm ocean water.

The Coriolis effect

the way Earth's rotation causes air and wind to curve.

Front

The place where two air masses meet

A cold front

what front forms when a cold air mass pushes into a warm air mass.

A warm front

what front forms when a warm air mass moves into a cold air mass.

A stationary front

what front forms when a cold and warm air mass meet, but neither moves.

An occluded front

what front forms when a cold air mass catches up to a warm air mass.

air mass

a large body of air with similar temperature and humidity that can bring changes in weather as it moves.

current

the steady flow of a fluid (such as air or water) within a larger body of that fluid.

Prevailing winds

air currents that blow mainly in one direction.

Gyres

circulate heat around Earth by moving warm water from the equator to the poles.

Energy from the Sun (solar radiation)

what drives the systems that shape Earth's weather and climate.

Greenhouse gasses

absorb and re-emit infrared radiation, helping to warm Earth's surface and lower atmosphere.

Electromagnetic (EM) waves

disturbances that travel through the electromagnetic field

a wave

disturbance that travels across space

Mechanical waves

Waves that require a matter medium to travel through

Periodic waves

waves that have a repeating pattern

frequency

how many wave cycles are generated in some amount of time.

wavelength

the distance from the beginning of one wave cycle to the beginning of the next cycle

wave speed

the distance traveled by a disturbance, divided by the time taken to travel that difference.

Amplitude

the maximum change from equilibrium caused by a wave.

Newton's first law

when the forces on an object are unbalanced its velocity changes. When the forces are balanced its velocity does not change.

Newton's second law

an object's acceleration depends on its mass and the strength of the net force exerted on it. It can be expressed as an equation:

force = mass * acceleration

Newton’s third law

if objects A and B interact, A exerts a force on B, and B exerts an equal-strength force on A, but in the opposite direction.

Contact forces

what forces require contact between objects. Examples are normal and friction forces.

Non-contact forces

what force can act without contact. These forces include gravitational, electric, and magnetic forces.

Net force

the combined effect of all the forces acting on an object.

speed

distance / time

Average speed

what measures how fast an object moves.

Velocity

what measures how fast and in what direction an object moves.

Chemical reactions

occurs when the bonds between atoms in the original substances are broken, and the atoms are rearranged into new combinations

Reactants

are written first in a chemical equation and are the substances we start with

Subscripts

are small numbers written after an element symbol and tell us the number of atoms of that element in a substance.

Coefficients

indicate the number of units of each substance involved in a chemical reaction. These are written before the formula of the substance they describe.

The law of conservation of matter

states that atoms are not created or destroyed in a chemical reaction; they are simply rearranged into new combinations.

chemical change / chemical reaction

occurs when a substance transforms into one or more new substances with new properties.

chemical property

a substance's ability to undergo a chemical change. It can only be observed by changing the identity of a substance.

Mixtures

can be separated into their components using physical methods like decantation, filtration, magnetism, or distillation.

Heterogeneous mixtures

mixtures that have visible boundaries and unevenly distributed components.