Science final

Friction

a force opposes the motion of another object; making the object slow down, or giving it traction to get moving

Gravity

the force that pulls down

Mass

the measure of the amount of matter in an object

Matter

Anything that has mass and takes up space

Acceleration/force relationship

the more force you apply, the greater the acceleration

Acceleration/mass relationship

the greater the mass, the more force necessary to get an object to accelerate

Momentum

how difficult it will be to stop an object;

Weight

is a measure of gravitational force between earth and an object

Speed

distance over time

Velocity

speed in a given direction

Acceleration

change in speed or direction;

rate of change of velocity

Balanced forces

do not change speed or direction

Unbalanced forces

do change speed or direction

Potential energy

stored energy

Kinetic energy

released energy

Inertia

The tendency of an object to resist a change in motion

Work

force applied over a specific distance

Distance

The length of a path between two points

Newton

unit for force

Force

a push or pull exerted on an object

Net force

the combination of all forces acting on an object

Newtons 1st law

An object at rest stays at rest and an object in motion stays in motion unless acted upon by an unbalanced force

Newtons 2nd law

Force equals mass times acceleration:

F\=ma

Newtons 3rd law

For every action there is an equal and opposite reactionMatter

MIXTURE

A mixture is matter that can vary in composition. Mixtures are combinations of two or more substances that are physically blended together. The amounts of the substances can vary in different parts of a mixture and from mixture to mixture.

ATOM

An atom is a small particle that is a building block of matter. At the center of a atom is the nucleus

SOLUTION

A solution is a homogeneous mixture. The largest amount of a substance that is found in a solution is called the solvent.

SUBSTANCE

A substance is matter with a composition that is always the same. This means that a given substance is always made up of the same combination of atoms for example aluminum.

HETEROGENOUS MIXTURE

A heterogeneous mixture is a type of mixture in which the individual substances are not evenly mixed. Because the substances in a heterogeneous mixture are not evenly mixed, two samples of the same mixture can have different amounts of the substance.

ELEMENT

An element is a substance that consists of just one type of atom

HOMOGENOUS MIXTURE

a homogeneous mixture is a type of mixture in which the individual substances are evenly mixed. In a homogenous mixture the particles of individual substances are so small and well mixed that they are not visable, even with most high powered microscopes.

COMPOUND

a compound is a type of substance containing atoms of two or more different elements, carbon, and oxygen bonded together

dissolve

To dissolve means to form a solution by mixing it evenly. Because the substances in a solution, or homogenous mixture, are evenly mixed, two samples from a solution will have the same amounts of each substance.

What are the parts of an atom?

The parts of an atom are the nucleus, protons, and neutrons.

What is a substance?

A substance is matter with a composition that is always the same.

How do atoms of different elements differ.

There are different atoms for each element.

Substances and mixtures are two types of

Matter

Use atom in a sentence.

An atom has a nucleus.

What does dissolve mean in your own words

Dissolve is to make a solution by mixing two substances evenly.

Explain why aluminum is a substance.

Aluminum is a substance because its mixture is all the same.

The number of always differs in atoms of different elements

protons

Distinguish between a heterogenous mixture and a homogeneous mixture.

a heterogeneous mixture is when the individual substances are not mixed evenly.

Homogenous is when the individual substance is mixed evenly.

Which term describes matter that is a substance made of different kinds of atoms bonded together.

Substance

Physical property

A physical property is a characteristic of matter that you can observe or measure without changing the identity of the matter

states of matter

Solid liquid and gas are all states of matter.

How do solids liquids and gases differ?

Solids are hard liquids are melted solids and gases are evaporated liquids.

Mass

Is the amount of matter in an object

Density

The mass per unit volume of a substance

volume

It is the amount of space something takes up.

Solutibility

Is the ability of one substance to dissolve in another

Physical change

A physical change is a change in size, shape, form, or state of matter in which the matter's identity stays the same. During a physical change, the matter does not become something different even though physical properties change.

Change in shape and size

Think about changes in the shapes and the sizes of substances and mixtures you experience everyday. When you chew your food you are breaking it into smaller pieces. This change in size helps make food easier to digest. When you pour a glass of juice you are changing the shape of the juice. Changes in the shape and size are physical changes. The identity of the matter has not changed.

Change in state of matter

Why does ice melt in your hand? Or, why does water turn to ice in the freezer? Matter such as water can change state. Recall from lesson 2 how the particles in a solid, a liquid, and a gas behave. To change the movement of particles, thermal energy must be either added or removed.

Adding thermal energy

When thermal energy is added to a solid, the particles in the solid move faster and faster, and the temperature increases. As the particles move faster, they are more likely to overcome the attractive forces that hold them together, the solid reaches its melting point. The melting point is the temperature at which a solid changes into a liquid.

After all the solid has melted, adding more thermal energy causes the particles to move even faster.

The temperature of the liquid increases. When the particles are moving too fast for attractive forces to hold them together the liquid is at the boiling point. The boiling point is the temperature at which a liquid changes into a gas and the particles spread out

Some solids change directly to a gas without first becoming a liquid. This process is called sublimation

Removing thermal energy

When thermal energy is removed from a gas, such as water vapor, particles in the gas move more slowly enough for attractive forces to pull the particles close together. Recall that condensation is the process that occurs when a gas becomes a liquid.

After the gas has completely changed to a liquid, removing more thermal energy from the liquid causes particles to move even more slowly. As the motion between the particles slows, the temperature decreases. Freezing occurs when the particles are moving so slowly that attractive forces between the particles hold them tightly together. Now the particles only can vibrate in place. Recall that freezing is the process that occurs when a liquid becomes a solid.

How can removing thermal energy affect the state of matter?

Removing thermal energy can affect the state of matter by causing it to freeze and turn into a solid.

Dissolving

Salt in water is an example of dissolving, salt dissolves in water. Because the identities of the substances water and salt are not changed, dissolving is a physical change.

Like many physical changes, dissolving is usually easy to reverse. If you boil salt water, the liquid water will change to water vapor, leaving behind the salt. You can see the salt because the particles that make up the substances do not change identity during a physical change

What happens when something dissolves?

When something dissolves it mixes evenly into a substance. Dissolving is also a physical change

Conservation of mass

During a physical change the physical properties of matter change. The particles in matter that are present before a physical change are the same as those present after the physical change. Because the particles are the same both before and after a physical change, the total mass before and after the change is also the same.

What is meant by conservation of mass?

Conservation of mass is that mass is conserved through changes

Use the term physical change in a sentence.

Physical change is when matter's shape or size is altered.

Describe how a change in energy can change ice into liquid water.

A change in thermal energy can turn ice into water because it makes the particles accelerate and go fast so it causes the ice to turn into water.

Which never changes during a physical change?

a. state of matter b. temperature c. total mass d. volume

volume

Relate what happens when something dissolves.

When something dissolves it dissolves evenly into a substance

Examine the graph below of temperature over time as a substance changes from solid to liquid to gas.Explain why the graph has horizontal lines

The graph has horizontal lines because it gets hotter as it turns from a solid to a liquid to a gas

Sublimation

Sublimation is the process by which solids change directly to a gas without first becoming a liquid.Atom

Electron

negatively charged particle that orbits the nucleus of an atom

Element

a pure substance made of one kind of atom

Matter

anything that has mass and takes up space (volume)

Neutron

a subatomic particle in the nucleus with no charge in the nucleus

Nucleus

The center core of an atom made of protons and neutrons

Periodic Table of Elements

a chart where all the elements are organized into periods and groups according to their properties

Proton

positively charged particle in the nucleus of an atom

3 subatomic particles

proton (nucleus)

neutron (nucleus)

electron (orbits nucleus)

Protons and neutrons

Make up the nucleus of an atom and give the atom its mass.

Protons and electrons

A neutral (no charge) atom has equal numbers of \____ and \_____

Atomic number

Number of protons and also the number of electrons in a neutral atom

Atomic mass or Atomic weight

Total number of protons and neutrons

Positive

Charge of the nucleus due to the charge of protons

Negative

Charge of electron cloud because the charge of electrons

Number of electrons

Same as number of protons in a neutral atom

Number of neutrons

Atomic mass minus Atomic number

12

Number of protons in and atom of magnesium (Mg)

3

Number of valence electrons in boron, aluminum, gallium, indium

16

Number of neutrons in a sulfur atom

Isotopes

Atoms of the same element (same number of protons) that have different numbers of neutrons

Ions

Positively or negatively charged atoms due to different number of protons than electrons

Positive ion

An atom that has lost some of its electrons; an atom with more protons than electrons