Science FINAL vocab

8th grade science final vocab credits to Mackenzie

Chadwick

discovered that in addition to protons, the nucleus also contains neutrons.

Combustion

a substance combines with oxygen and releases energy (thermal or light) Creates Fire.

Rutherford

most of an atoms mass and positive charge is concentrated in a small area in the center called the nucleus.

reaction rate

Increases \________ because there are more particles to collide with each other.

Mixtures

\________ can be solid or gasses.

hydronium ion

Produces a(n) \________ when dissolved in water.

Granite

\________ is an example of a solid.

Thompson

\________- cathode rays (made of electrons) are negatively charged, used positively and negatively charged plates.

hydroxide ion

Produces a(n) \________ when dissolved in water.

Metalloids

\________ are in the middle of the metals and the nonmetals.

Neutrons

\________: In the nucleus with the protons; neutral.

Physical change

\________: you have the same chemical thingamabobbers.

Chemical reactions

\________ occur faster if the particles collide more often or if the particles are moving faster when they collide.

Dalton

\________- atoms can not be created or destroyed, atoms combine in specific ratios.

Democritus

\________- different types of matter are made from different atoms.

Water molecules

\________ have a lot of polarity and the ability to form hydrogen bonds.

Electron Cloud

\________: surrounds the atom.

unit of solvent

Concentrated: more solute per \________.

Dimitri Mendeleev

\________ categorized in rows by atomic mass (Mendeleev)- used repeating chemical /physical properties to make columns.

surface area

Increased \________ increases the rate of a reaction because more particles on the surface of the solid come in contact with the particles of another substance.

electron cloud

Electrons: In the \________;- 1 charge.

Democritus

different types of matter are made from different atoms

Dalton

atoms cannot be created or destroyed, atoms combine in specific ratios

thompson

cathode rays (made of electrons) are negatively charged, used positively and negatively charged plates

rutherford

most of an atoms mass and positive charge is concentrated in a small area in the center called the nucleus

chadwick

discovered that in addition to protons, the nucleus also contains neutrons

bohr

said that the neutrons and protons are in orbits (found out later that they were not)

modern atomic model

electron cloud

Proton

rutherford

electron

Thomson

neutron

Chadwick

in the center

Nucleus

surrounds the atom

Electron Cloud

In the nucleus; +1 charge

protons

In the nucleus with the protons; neutral

neutrons

In the electron cloud; -1 charge

electron

Group 1

Alkali metals

Group 2

Alkaline earth metals

Group 3-12

Transition metals

Group 17

Halogens

Group 18

Noble Gasses

Most common element in the universe

hydrogen

ionic

non-metal and Metal

covalent

non metal and nonmetal

metallic

metal and metal

chemical change

you end up with something different

physical change

you have the same chemical thingamabobbers

Synthesis

2 reactants and 1 product (2 or more substances combine and form 1 compound)

Decomposition

1 reactant and 2 products (1 compound breaks down and forms 2 or more compounds)

single replacement

1 element replaces another in a compound

Double replacement

ions in 2 compounds switch places (forms 2 new compounds)

Combustion

a substance combines with oxygen and releases energy (thermal or light) Creates Fire

Endothermic reactions

absorb thermal energy (more energy is needed to break the bonds than is produced by breaking the bonds) (decomposition reactions) (feels Cold)

Exothermic reactions

release thermal energy (less energy is needed to break the bonds than is produced by breaking the bonds) (synthesis reactions)

dilute

less solute per unit of solvent

concentrated

more solute per unit of solvent

Acid

red

Base

blue

Wave

A disturbance that transfers energy from place to place without transferring matter

Mechanical wave

A wave that can travel only through matter

Medium

A material in which a wave travels

Transverse wave

a wave in which the disturbance is perpendicular to the direction the wave travels

Crest

The highest point of a transverse wave

Trough

The lowest point of a transverse wave

Longitudinal wave

makes the particles in a medium move parallel to the direction that the wave travels

Compression

The regions of a longitudinal wave where the particles in the medium are CLOSEST together

Rarefaction

The regions of a longitudinal wave where the particles of the medium are FARTHEST apart

Electromagnetic wave

A wave that can travel through empty space and through matter

Amplitude

The maximum distance that the wave moves from its rest position

Wavelength

The distance from one point on a wave to the same point on the next wave

Frequency

Number of wavelengths that pass by a point each second

Absorption

The transfer of energy by a wave to the medium through which it travels

Transmission

The passage of light through an object

Reflection

The bouncing of a wave off a surface

Law of reflection

When a wave is reflected from a surface, the angle of reflection is equal to the angle of incidence

Refraction

The change in direction of a wave that occurs as the wave changes speed when moving from one medium to another

Diffraction

The change in direction of a wave when it travels by the edge of an object or through an opening

Interference

Occurs when two or more waves overlap and combine together

fluid

any substance that can flow and take the shape of the container that holds it

pressure

the amount of force per unit area applied to an object's surface

buoyant force

an upward force applied by a fluid on an object in the fluid

atmospheric pressure

the ratio of the weight of all the air above you to your surface area

Archimedes' Principle

the weight of the fluid that an object displaces is equal to the buoyant force acting on the object

Pascal's Principle

when pressure is applied to a fluid in a closed container, the pressure increases by the same amount everywhere in the container

Bernoulli's Principle

the pressure of a fluid decreases when the speed of the fluid increases

drag force

a force opposes the motion of an object through a fluid

Boyle's Law

If you decrease the volume of a container (but keep the temperature the same), the pressure in the container will increase (PiVi\=PfVf)

Charles' Law

the volume of a gas increases when the temperature increases (Vi/Ti\=Vf/Tf)

Electromagnetic wave

a wave that can travel through empty space and matter

Radiant energy

energy carried by an electromagnetic wave

Electromagnetic spectrum

the entire range of electromagnetic waves with different wavelengths and frequencies

Radio wave

a low frequency, low energy electromagnetic that has a wavelength longer than about 30 cm

Microwave

is a low frequency, low energy electromagnetic wave that has a wavelength between about 1 mm and 30 cm

Infrared wave

an electromagnetic wave that has a wavelength shorter than a microwave but longer than light

Ultraviolet wave

an electromagnetic wave that has a slightly shorter wavelength and frequency than light and carries energy to cause chemical reactions

X-ray

a high energy electromagnetic wave that has a slightly shorter wavelength and higher frequency than an ultraviolet wave

Gamma ray

a high energy electromagnetic wave with a shorter wavelength and higher frequency than all other types of electromagnetic wave

force

A push or pull exerted on an object

contact force

a push or pull on one object by another that is touching it

non-contact force

a force that one object can apply to another object without touching it