Science Unit 3

Energy

The ability to do work. It is quantifiable and objects that possess energy have the ability to change itself or its surroundings.

Mechanical Energy

A group of energy that deals with motion

GPE

the energy stored in an objects location in the gravitational field

GPE=0

The point where height is measured from.

Kinetic Energy

the energy an object has because of its movement

Efficency

How much of a devices available energy is used to accomplish the desired task. Nothing is 100% efficent due to friction and air resistance

Conservation of Energy

The amount of energy always stays the same, it just transitions from one form to another. Energy is neither created nor destroyed.

Bohr Model

Not accurate to the workings of an atom, but helpful in visualization.

3 parts of an atom

Proton, Neutron, Electron

Protons

Mass 1, charge +1, In nucleus, determines what the element is

Neutrons

Mass 1, charge 0, in nucleus, determines the element’s isotope

Electrons

Mass 0, charge -1, outside nucleus, determines how an atom will chemically react with others

Mass Number

Protons + Neutrons

Atomic Number

Amount of Protons

Isotopes

The same atom with a different number of neutrons, same amount of protons

Charge of an atom

Protons-Electrons. To change the charge add or take away electrons. Influences bonding and chemical reactions

Ion

non-neutral atom

Ionization

Proccess of adding or subtracting electrons

Gravitational Force

Long-range, Weakest, Causes things to come together, everything with mass has gravity, can only be seen with large objects

The Strong Nuclear Force

An attractive force that keep the nucleus in an atom together, only acts on super small distance, strongest, created by protons and neutrons interacting

Weak Nuclear Force

Allows one type of particle to turn into another, responsible for radioactive decy, 3rd strongest, only over small distance, created by interactions in the nucleus

Electromagnetic Force

describes the force acting on electrical charges and magnets, 2nd strongest, long range, created by the prescence and movement of electrical charges, keeps electrons attached to the nucleus, explains: Light, Electricity, Chemical reactions, and why things have shap

Force

A push or pull, vector quantity, can be represented by arrows, measured in neutrons

Equilibrium

When the forces acting on something are balanced, causing it to keep doing what it’s doing. (being at rest, constant speeds)

Newtons 2nd law

If the forces are unbalanced, an object will change motion

A book stays on a table because

Electromagnetic force, Gravitational force

What holds and atom together

Electromagnetic, Strong Nuclear Force

Wave

A disturbance that transfers energy from one place to another.

Medium

what the wave travels through. Determines wave speed

Mechanical waves

Waves that require a medium to move through. The particles of the medium are not carried with the wave

Transverse waves

Particles move perpindicular to the wave direction

Longitudinal

Particles move parralell to the wave direction

Wavelength

distance from one crest to another or the distance from one compression to another, measured in meters

Amplitude

the height of a crest from the equilibrium position, or the area of highest density

Period

T, time per cycle, measured in seconds

Frequency

Cycle per time, measured in Hertz

Speed

how far a crest travels at a given amount of time. If wave speed is constant then wwavelength and frequency are inversley related. bigger frequency shorter wavelength

Light

The smalled quantity of energy that can be transported, a photon

Photon

a particle without a real size that cannot be split only created or destroyed

Wave Particle duality

has wave-like or particle-like characteritics depending on the situation

We can see visible light because

the only electromagnetic waves that can go in water, where most eyes evolved

Electromagnetic waves

Where two fields intertwine (Electric and magnetic), which makes it self replicating. Means it doesn’t need a medium to travel through

Electromagnetic waves from longest wavelength to shortest

Radio, Micro, infared, visible, uv, x-ray, gamma

False colors

To see frequencys not included in visible life, we assign false colors to represent them

c

Speed of light, fastest thing in the universe

high energy photon colors

blue

low energy photon colors

red

doppler affect

causes a shift in electromagnetic waves, compressing waves in the directions its going. Approaching is more blue, leaving more red

spectroscopy

the study of light emitted from atoms and molecules

Continuous Spectra

When a solid or dense gas is heated, it emits all wavelenghts of light

Emmision Spectra

Absorbtion Spectra