physics 2.1-2.4

matter

Anything that has mass and takes up space

Inertia

The tendency of an object to remain in its present state of motion

Mass

Represents how much force is required to change the objects state of motion

Weight

Represent the amount of force the earths gravity exerts on an objects mass

Density

The ratio of an objects mass to its volume

Specific gravity

The ratio of a given samples density

Relative density

Other term used for “specific gravity”

Molecule

A chemical combination of two or more atoms

Elemental molecules

Elements that are the same

Compound

Atoms in a single molecule that are different elements

Pure substance

A substance only containing one kind of atom or molecule

Mixtures

physical combinations of two or more elements or compounds

Homogeneous mixtures

A mixture that has a uniform composition and that are evenly distributed

Heterogeneous mixtures

A mixture in which the components are not evenly distributed

Four states of matter

Solids, liquids, gas, and plasma

Solids

has definite shape and volume

Liquids

Has a definite volume but not a definite shape, a liquid will also take up the shape of its container

Gases

Has separate particles that will spread to take up the shape of its container, but it has no definite shape or volume

Plasma

A gas with positive ions and separated electrons

Atom

A incredibly small particle

Nucleus

The collection of particles fixed at the center of an atom

Electrons

Smaller particles moving about the nucleus

Protons

A positively charged particle

Atomic number

The number of protons in a given element

Neutron

The largest atomic particle that has a neutral charge

Mass number

The sum of the number of protons and neutrons in the nucleus

Isotopes

Atoms with the same atomic number but different mass numbers

Atomic mass

The weighted averaged mass of all isotopes of an element

AMU

The atomic mass unit

Electron

A negative charged particle that makes up an atom

Ion

Charged particle that gains or loses electrons

Anion

An atom with excess of electrons

Cation

An atom with a deficiency of electrons

Element

Any substance that cannot be broken down by chemical means intro a simpler substance

Horizontal periods

Row of elements that have the same number of electron shells around the nucleus

Valence electrons

Electrons in the outermost electron layer

Vertical groups

Columns of elements that have the same number of valence electrons

Photons

Tiny particles of light

Nuclear mass defect

When the neutrons and protons are drawn together into the nucleus by the strong nuclear force

Subatomic particles

Particles smaller than atoms, particles that compose the atom that exist or the atom and separate it

Elementary particles

Particles with no components, no building blocks or smaller parts

Quarks

Fundamental particles that makes up protons and neutrons

Hadrons

Any substance believed to contain quarks

Mesons

Substances containing 2 quarks

Baryons

Substances containing 3 quarks

Gluon

A particle that acts like “glue” to hold quarks together inside particles

Leptons

Elementary particles that do not feel the strong nuclear force

Neutrino

Tiny neutral particle that is in the lepton family

Positron

Discovered in 1932, a positively charged electron

Gamma radiation

A type of nuclear energy radiation made of photons

Pair production

A process where energy is converted into matter

Electromagnetic radiation

Any type of emitted energy