# Science Final: Vocab

## 28 terms · Atoms to Forces

### friction

a force that opposes motion caused by tiny hills and valley

### force

a push or a pull on an object

### net force

all the forces acting on an object combined

### weight

measurement of the gravitational force on an object (measured in newtons or pounds)

### mass

the amount of matter in an object (measured in grams)

### gravity

the force of attraction between two objects

### atomic mass

average mass of a particular element (shown on Periodic Table)

### Newton

Sir Isaac Newton, a British scientist, defined the universe's three laws

### speed

rate at which an object moves (∆ distance divided by ∆ time)

### newtons (N)

the SI unit of force

### atoms

the smallest piece an element can be broken down to while retaining the element's properties

### protons

positively charged particles in the nucleus that are 1 amu

### atomic number

the amount of protons in an atom of a particular element

### inertia

the tendency of all objects to resist any change in motion

### velocity

the speed of an object in a particular direction

### isotopes

a form of an atom with a specific number of neutrons

### neutrons

part of an atom that is 1 amu and has no charge in the nucleus

### electrons

part of an atom that is 0 amu and has negative charge in outer rings (orbitals)

### motion

when an object changes position when compared to a reference point

### acceleration

the rate at which velocity changes

### balanced forces

forces that don't cause changes of motion or direction

### mass number

rounded atomic mass

### air resistance

type of friction that acts as an object moves through air

### unbalanced forces

forces that produce a change in motion or direction (acceleration)

### gravity (in an atom)

it pulls objects toward each other, but the particles are small so the gravity is small

### electromagnetic force

positives repel each other, negatives repel each other, opposites attract, neutral and anything aren't affected

### strong force

the force in an atom that is stronger than the electromagnetic force and holds the nucleus together

### weak force

the force in an atom that is important in radio-active and unstable atoms; plays a role in the nucleus changing into electrons and protons