science 8 finals :scream:

compound

a mix of chemicals that can only be broken down by chemical changes

matter

anything that has mass and volume (takes up space)

physical property

a quality that can be observed without changing chemical identity

chemical property

a quality that can only be observed when changing chemical identity, ability of matter to react with another substance to form a new substance(s)

physical change

a change of matter that does not change the chemical identity

chemical change

change of matter that produces a new substance(s)

difference between a change and a property

a property is a quality, a change is a change idk

density

d = m/v (mass/volume)

three main states of matter

solid, liquid, gas

atoms in a liquid sate

they slip and slide past each other

what happens to liquid particles as it changes to a gas

the atoms gain more energy and they move faster and farther apart

what happens to liquid particles as it changes to a solid

the atoms lose energy and move slower and closer together

units to measure density

g/ml or g/cm^3

sublimation

when solid turns to gas

what does KMT state

all matter has energy and all matter is constantly in motion

what matter is made of

atoms

subatomic particles

protons, neutrons, electrons

where are neutrons

in the nucleus

where are protons

in the nucleus

where are electrons

in the energy shells, surrounding the nucleus

what charge does a neutron have

none/neutral

what charge does a proton have

positive

what charge does an electron have

negative

what does the 8 signify

it’s the atomic number, it represents how many protons there are in that element

what does the O signify

it’s the atomic symbol

what does the 15.999 signify

the atomic mass, which is # of protons + # of neutrons

how many protons, electrons, and neutrons are there in a neutral neon atom

10 protons, 10 electrons, 10 neutrons

mixture

a mix of things that can be separated by physical changes

element

a pure substance that cannot be broken down anymore (just trust me bro)

period

a row on the periodic table of elements that have the same number of electron shells

group/family

a column on the periodic table of elements that all have the same number of electrons on the outermost shell

alkali metals

group 1 on the periodic table

alkaline earth metals

group 2 on the periodic table

halogens

group 17 on the periodic table

nobel gasses

group 18 on the periodic table, and they are the most stable because they have full shells

emr

electromagnetic radiation, light energy

emr spectrum (lowest to highest frequency)

radio waves, micro waves, infrared, visible light, uv rays, x-ray, gamma rays

hertz/frequency

cycle per second, each time the wave passes through the rest position

ray model

shadow model, shows light travels in a straight line and cant bend around objects

wave model

light shining through gaps and making a pattern, shows that light spreads out with wave-like properties

particle model

photons hitting metal, electrons only being given off at certain frequencies shows that light has to interact in packets of certain amounts of energy

ionizing

waves that have the ability to detach electrons from atoms and giving them a charge, exposure can cause tissue and organ damage

reflection

light bounces off something

absorption

light energy is trapped

transmission

light passes through

refraction

path of light bends and speed of light changes (light bends towards the normal when moving into denser media and vice versa)

media/medium

matter that light interacts with

opaque

no light is transmitted, light is either reflected or absorbed

translucent

some light is transmitted and scattered, some light is absorbed or reflected

transparent

all light is transmitted, a small amount of light is scattered

plane mirror reflection

same distance, same size, upright, virtual

concave mirror reflection close to fp

farther, larger, inverted, real

concave mirror reflection far from fp

closer, smaller, inverted, real

concave mirror reflection in between mirror & fp

farther, larger, upright, virtual

convex mirror reflection

closer, smaller, upright, virtual

rainbow formation

white light enters the raindrop and refracts, then reflects off the back of the raindrop where it starts to break into colors, then refracts more as light leaves the raindrop and splits fully

mirage formation

on a really hot day, air splits into layers by heat, with hot air closer to the ground. light refracts more and more at each hotter layer and eventually doesnt touch the ground and travels in a u shape until it hits our eyes. our eyes cant comprehend light bending so we see an image on the ground instead of the ground.

converging lens

has at least one convex surface, is thicker in the center, used to correct hyperopia

diverging lens

has at least one concave surface, is thinner in the center, used to correct myopia

myopia

nearsightedness, caused by long eyeball or curved cornea, can be treated by diverging lens or laser eye surgery

hyperopia

farsightedness, caused by short eyeball or flat cornea, can be treated by converging lens or laser eye surgery

pupil

black part of eyeball on the outside that takes the light into the eye

iris

colored circle of muscle, controls the amount of light entering the eye

cornea

clear film that covers the eye

sclera

the white of the eye

lens

convex lens inside eye that focuses light to the retina

retina

film on the back of the eye where an image is formed

ciliary muscles

controls the shape of the lens to adjust to distance

optic nerve

sends the image formed at the retina to the brain

vitreous humor

clear gell that fills the inside of the eyeball and gives it shape

cataracts

protein buildup in the lens that causes cloudy vision or loss of vision, can only be treated with surgery

astigmatism

elongated cornea, causes images to be blurry at all distances, can be treated by glasses, contact lenses, or laser eye surgery

continental drift hypothesis

theory proposed by alfred wegener that continents used to be connected because they were similar shapes, had similar fossils (ie fern fossils in all southern continents), similar mountains, and glacial striations/fossilized forests

alfred wegener

man who proposed continental drift hypothesis

pangaea

the supercontinent from 200 million years ago when all continents were connected

fixism

the theory that continents had always been where they were, widely regarded as fact until continental drift hypothesis

crust of earth

thin layer of solid rock surrounding the earth, has oceanic crust (made of basalt) and continental crust (made of granite). sometimes contains lithosphere

upper mantle

layer just below crust, very top of the upper mantle is solid and below is softer rock that can flow. contains lithosphere and asthenosphere

lower mantle

below upper mantle, made of denser rock

outer core

below lower mantle, made of iron and nickel, is liquid

inner core

center of the earth, below outer core, is made of iron and some nickel, temp >5000 degrees and is solid from the high pressure of above layers

mid ocean ridges

mountain ridges along the ocean floor, earthquakes and volcanic eruptions occur

trenches

long, narrow valleys (depressions) in the ocean floor, can be thousands of km long and deep

sea floor spreading

the process of magma rising to the surface of ridges and forming new ocean crust. magma emerges in the center and pushes older crust to the sides and below other plates. explained how continents were able to move, because the rock and plates were moving beneath them.

subduction

when denser crust goes below the less dense crust

theory of plate tectonics

earths crust is made of tectonic plates that float ont the fluid rock in the mantle. the plates move very slowly. it explains seafloor spreading/continental drift, earthquakes, volcanoes, and formations of mountains.

lithosphere

outer layer of solid rock and plates composed of crust and part of the upper mantle, when plates interact it causes geological activity

asthenosphere

the soft, flowy part of the upper mantle that is hot and behaves like plastic. this enables plates to move. tectonic plates float on top of it.

divergent plate boundaries

when tectonic plates separate and create new oceanic crust; can also occur in the middle of continents (continental rifting)

convergent plate boundaries

when two plates collide, subduction occurs and causes trenches, often induces earthquakes

oceanic-continental plate convergence

oceanic plate goes beneath continental plate; may form mountains or volcanoes (from the release of pressure from the upper mantle)

oceanic-oceanic plate convergence

subduction with ocean crust occurs, may form volcanic island arc and trenches

volcanic island arc

a belt of volcanoes that occur from plate oceanic plate convergence

continental-continental plate convergence

no subduction occurs, one plate is shoved beneath the edge of the other and creates mountain ranges as the crust goes upwards

transform plate boundaries

when two plates slide past each other; earthquakes are common

mantle convection

warmer, less dense material in the mantle rises as cooler, more dense material sinks; causes currents in the mantle and drags plates with it

ridge push

new material pushes older material aside, causing tectonic plates to move apart (ex. magma hardening in the crust causing plates to move), occurs at diverging plate boundaries; includes seafloor spreading, continental rifting, and new rock formations

slab pull

movement of plates downwards, occurs at converging plate boundaries where subduction may occur; responsible for mountains, volcanoes, earthquakes, and trenches

earthquakes

a natural movement or vibration when earth’s crust shifts. when pressure is applied on a plate too quicky or strongly, the rock will break in the form of an earthquake

focus

the point where the movement in the rock during an earthquake occurs