science unit 1 test

independent variable

the variable that’s changing

dependent variable

the variable that’s being measured

controlled variable

the variable that stays the same

correlation

a mutual relationship between two or more things

refraction

the bending of light which passes at angle through one medium into another

medium

the substance that transfers the energy or light

incident ray

the ray of light falling on the reflected surface

interface

surface separating two phases of matter, can be solid, liquid, or gas

angle of incidence

the angle formed between the normal and incident ray

angle of refraction

the angle formed between the normal and the refracted way

normal

the ray that is at 90 degrees on the point of incidence to the reflecting surface

atom

the smallest unit of matter that holds all the chemical properties of elements

electron

a negatively charged particle found in the orbitals of an atom

proton

a positively charged particle found in the nucleus of an atom

neutron

a neutral charge particle found in the nucleus of an atom

atomic number

the number of protons an element has

atomic mass

the number of protons and neutrons an element has

nucleus

the core of an atom, contains protons and neutrons

energy level

also known as orbitals or shells, holds the electrons in an atom

valence electron

the electrons in the last orbital of an atom

period

horizontal row on the periodic table

group

column on the periodic table

metal

solid, high melting points, low density, good conductors, can be mixed together to make an alloy, malleable, ductile

non metal

poor solubility, soft, low density, insulators, dull, low melting points

alkali metals

lustrous, malleable, soft, ductile, good conductors, all oxidize, react vigorously with water

alkaline earth metals

highly reactive, oxidize, low melting points, good conductors, metallic, ductile, lustrous, malleable

halogens

reactive, all oxidize, non metals, noticeable colour

noble gases

glow with bright colours in reaction to electricity passing through them, colourless, all gases

pure substance

a single kind of matter that cannot be separated into other kinds of matter

element

a chemical substance that cannot be broken down into other substances

compound

a substance composed of two or more different elements chemically bonded together

mixture

a combination of two or more substances that are not chemically bonded together

homogenous mixture

a type of mixture where there is only one phase of matter throughout the substance and the proportions are the same

heterogenous mixture

a type of mixture that consists of different substances or components that are visibly distinguishable

stable octet

when the last orbital has 8 valence electrons

ozone

colourless gas, exists in the stratosphere

global warming potential

how well a particular gas absorbs and scatters infrared radiation

greenhouse effect

trapping of the sun’s warmth in a planet’s troposphere from the transparency of the atmosphere

insolation

the amount of solar radiation received on a given surface in a specific time period

anthropogenic greenhouse gas source

combustion of fossil fuels, transportation areas, and deforestation

natural source greenhouse gas source

volcanoes, forest fires, and decomposing organic matter

covalent bond

when the one or more pairs of electrons of atoms are equally attracted to each others nuclei

molecule

a group of atoms bonded together

wave crest

the highest point of a wave

wave trough

the lowest point of a wave

amplitude

the power of a wave from the equilibrium position to the crest

rest position or equilibrium position

the halfway point between the trough and the crest

wavelength

the length of a wave

frequency

the number of waves in a certain amount of time

inverse relationship

when one variable decreases and another increases

convection

a movement in a gas or liquid when the warmer parts move up and the cooler parts move down

conduction

the transfer of energy, such as heat or an electric charge through a substance

radiation

energy that comes from a source and travels through space at the speed of light

electromagnetic spectrum

the range of frequencies of electromagnetic radiation and their wavelengths

radio waves

a type of electromagnetic radiation, longest wavelength, used for communication purposes

microwaves

found at the higher frequency end of the radio spectrum, shorter wavelengths than radio

infrared light

longer wavelengths than visible light but shorter than microwaves

visible light

the human eye can view this light

ultraviolet

a form of radiation that is emitted by the sun and artificial sources, shorter than visible light, longer than x ray light, used in tanning beds

visible light spectrum

the segment of the electromagnetic spectrum that the human eye can view

x rays

can pass through most objects, higher energy, shorter than uv light, longer than gamma rays

gamma rays

the shortest wave length on the electromagnetic spectrum

luminescence

the emission of light by a substance as a result of a chemical reaction

incandescence

emission of light due to a change in temperature, e.g. old light bulbs

chemiluminescence

light is released due to a chemical reaction without a change in temperature, e.g. mixing two different chemicals together

bioluminescence

a biochemical reaction inside a living cell produces light

triboluminescence

light is produced during the breaking of chemical bonds when a material is pulled apart, ripped, scratched, crushed, or rubbed, e.g. drilling quartz

phosphorescence

when a substance absorbs one colour of light but then emits a different one slowly

fluorescence

when a substance absorbs one colour of light then emits a different one immediately

electric discharge

the release and transmission of electricity in an electric field through a medium such as gas

photon

a particle of light which is essentially a packet of electromagnetic radiation

greenhouse gas

gases in the earth’s atmosphere that trap heat

methane

colourless, odorless, highly flammable gas, composed of carbon and hydrogen

carbon dioxide

a colourless and non flammable gas, humans exhale this substance

water vapour

water in gas form instead of liquid form

chlorofluorocarbons

non toxic, non flammable chemicals containing atoms of carbon, chlorine, and fluorine

nitrous oxide

odorless, colourless, non flammable gas, also known as laughing gas