Science 8 - Unit 3 test

Temperature

a measure of the average kinetic energy of the atoms of a substance.

Heat

the energy transferred from a substance at a higher temp to one at a lower temperature.

Conduction

the energy transferred from fast moving atoms to slower moving.

How does heat transfer?

By the fast-moving molecules hitting the slow moving atoms and speeding them up. In this way, its transferring kinetic energy to one another. This works the same for cooling a substance.

What makes an object a good conductor?

A substance that atoms are more compact and tight.

Solution

2 substances combined forming a mixture.

Solute

the substance that gets dissolved.

Solvent

the substance that does the dissolving (usually in liquid form).

Insoluble

Does not dissolve in the solvent.

Solubility

the ability for a solute to dissolve in a solvent and is affected by temperature and pressure.

Mixture

a material composed of two or more substances

What is on the X-Axis of a solubility graph?

Temperature (Celcius)

What is on the Y-Axis of a solubility graph?

the solubility grams per 100cc

Increasing slope means

the substance is a solid

Decreasing slope means

the substance is a gas

What are the two ways to classify matter?

Pure substances and Mixtures

What is a Pure substance and what are the two groups under it called?

Has a constant composition, Element, Compound

Elements

Composed of only ONE atom Ex. periodic table

Compound

Composed of two or more atoms combined chemically Ex. H20, NaCI (salt)

What is a Mixture and what are the two groups under it called?

Physically composed by two or more substances, Homogenous and Heterogeneous.

Homogenous

cannot see particles because they are well mixed Ex. filtered tea, sugar water

Heterogeneous

can see particles because it is “less” mixed Ex. Orange Juice with pulp

Physical property

observed without changing the chemical composition (identity) of the substance Ex. Density, Conductivity, Boiling point, Freezing point, Solubility.

Physical change

changes the matter without changing what its made of. It usually can be undone Ex. melting, dissolving, changes in size and shape, boiling, mixing

Chemical property

describes the ability of a substance to undergo specific chemical change (changing the identity of a substance) Ex. Flammability, acidity, and types of reactivity

Chemical change

It will change the chemical composition of the substance such as color and temp and usually cannot be undone Ex. burning, cooking, rusting, rotting

Super saturated solution and what does it produce?

A super saturated solution means the maximum amount of solute had dissolved and no more can. This causes the process of crystilizartion of the solute.

what does it mean if a solution is below the line?

the solution is unsaturated

what does it mean if a solution is above the line?

the solution is a super saturated solution

what does it mean if a solution is on the line?

the solution is saturated

as temperature increases, what happens to the solubility of a solid

increases

as temperature increases, what happens to the solubility of a gas

decreases