Study for Science Final

Electrons(-)

- Have a negative charge

- Located outside the nucleus of an atom in the electron cloud

- The number of electrons can differ in atoms of the same element; these are ions

Protons(+)

- Have a positive charge

- Determine the identity of the element and the atomic number

- Located inside the nucleus of the atom

Neutrons(n)

- Have no charge are neutral

- Located inside the nucleus of the atom

- The number of neutrons can differ in the - atoms of same element: these are isotopes

Force

Push or pull exerted on an object, measured in newtons (N)

Newton

A unit of measure that equals the force required to accelerate 1 kilogram of mass at 1 meter per second

Net Force

The overall force on an object when all the individual forces acting on it are added together

Balanced Force

When the net force on an object is 0 N(object doesn't move )

Motion

An object's change in position relative to a reference point

Unbalanced Force

When the net force on an object is not 0 N; object moves

Newton first law of motion

An object at rest will remain at rest and an object in motion will stay in motion unless it is acted on by an unbalanced force

newton second law of motion

An object's acceleration depends on its mass and on the net force acting on it (F=ma)

newton third law of motion

If one object exerts a force on another object, then the second object exerts a force of equal strength and opposite direction on the first object

Inertia

The tendency of an object to resist a change in motion

Constant veloctiy

A speed that does not change how fast it is, or the direction that it is in

Accelaration

The rate at which velocity changes over time; an object accelerates if its speed, direction, or both change (a=F/m)

Momentum

The product of an object's mass and velocity

Law of conservation of momentum

The rule that in the absence of outside forces, the total momentum of objects that interact does not change

Buoyant Force

The upward force exerted by a fluid on a submerged object

Independent variable

Can be manipulated; this is the variable the scientist changes

dependent variable

Responding; this is the variable that the scientist measures or observes

constants in expeirmental design

Are known as standardizing variables that need to stay the same for each test in a controlled experiment

experimental control

A control is used to evaluate whether an experiment is working

3 things for a fair expeiremnt

- Precise & Accurate Measurements,

- Repeated Trials

- Detailed Notes

mixture

Is made when two or more substances are combined, but they are not combined chemically

propertires of a mixture

- The components of a mixture can be easily separated

- The components each keep their original properties

- The proportion of the components is variable

homogeneous mixture

All the substances are evenly distributed throughout the mixture

(salt, water, air, blood)

Heterogeneous mixture

The substances are not evenly distributed

(CCCookies, pizza, rocks )

Solution

Is a mixture where one of the substances dissolves in the other

Solute

A substance that dissolves in a liquid; (e.g., salt in water)

Solvent

A substance, usually a liquid that dissolves a solute(solid, liquid,gas ) to form a homogeneous solution

pH scale

Is used to classify substances as acids and bases, 0-14

Acids

Have a pH number that is less than 7

Bases

pH number more than 7

MIX

M: Manipulated

I: Independent

X: X-axis

DRY

D: Dependent

R- Responding

Y: Y-axis

litmus paper thing

Acids taste sour and turn blue litmus red, whereas bases taste bitter, feel soapy, and turn red litmus blue. They neutralize each other to form salt and water.

Phase Changes

Period of Periodic table

the 7 horizontal rows

Group of Periodic table

the 18 vertical columns