Unit 2 Science Test

heterogeneous mixture

A mixture that is not uniform in composition; components are not evenly distributed throughout the mixture

homogeneous mixture

A mixture in which substances are evenly distributed throughout the mixture

Solvent

A liquid substance capable of dissolving other substances ; the substance in which the solute dissolves.

Solute

A substance that is dissolved in a solution.

Colloid

heterogeneous mixture whose particles never settle

Suspension

A mixture in which particles can be seen and easily separated by settling or filtration

Solubility

The ability to dissolve in another substance

Factors affecting solubility

properties of solute and solvent(concentration) , temperature, pressure

When a solution reaches the point where it cannot dissolve any more solute what is it considered?

saturated

What happens when the temperature of a SOLID solute is increased?

increases the amount of SOLID solute that can dissolve

What happens when the pressure of a gas is increased?

The solubility of the gas increases.

Why does raising the temperature increase the rate at which a solute dissolves?

The increase of temperature causes the molecules to move faster and allows the solute to break up easier.

ice melting is an example of what type of change?

physical change

metal rusting is an example of what type of change?

chemical change

physical change

a change of matter from one form to another without a change in chemical properties

chemical change

A change that occurs when one or more substances change into entirely new substances with different properties.

Matter

Anything that has mass and takes up space

Burning is what type of change?

chemical change

Boiling and freezing are what type of change?

physical change

exothermic reaction

A reaction that releases energy in the form of heat

endothermic reaction

A reaction that ABSORBS energy in the form of heat

catalyst

substance that speeds up the rate of a chemical reaction

Products in a chemical equation

Ending substances, after the arrow; the substance that is formed from the reactants

Reactants in a chemical equation

beginning substances, before the arrow; what is reacting to create the product

How does rust form?

Through a chemical reaction between iron and oxygen

What causes rust on a steel car?

oxygen in the air chemically combines with the iron in the steel to form rust

synthesis reaction

a reaction in which two or more substances combine to form a new compound

replacement reaction

A reaction where compounds are rearranged into different compounds.

decomposition reaction

a reaction in which a single compound breaks down to form two or more simpler substances

balanced chemical equation

chemical equation with the same number of atoms of each element on both sides of the equation

open system

A system in which matter can enter from or escape to the surroundings.

closed system

A system in which no matter is allowed to enter or leave

What kind of problem can develop from using synthetic materials?

It is not biodegradable so it can cause an increase in pollution

Was superglue created on purpose of accidentally?

accidentally

Benefits to synthetic food products

1. keeps food fresh longer
2. cheaper to produce in large amounts
3. can substitute for unavailable or scarce foods

Drawbacks to synthetic food production

1. affects health
2. unknown future effects

Polymer

large compound formed from combinations of many monomers

Monomer

small chemical unit that makes up a polymer