Chemistry Semester 1 Review

1 cm³

1 mL

Density

mass/volume

q=mc∆T

represents the heat energy absorbed or released by a substance, where q is the heat energy, m is the mass, c is the specific heat capacity, and ∆T is the change in temperature.

physical properties

Physical properties can be seen or measured without changing the substance.

a) Density

b) Color

c) Melting point, boiling pt., freezing pt.

d) Smell

Chemical properties

require the substance to change to a new substance.

a) Flammability

b) Reactivity with certain chemicals.

physical change

when the physical properties of matter are changed but the substance itself does not change. This usually involves changing the state of matter (from liquid to gas, etc.)

chemical change

when a new substance is created. It involves either a color change, creation of a gas, formation of a precipitant (solid) or a temperature change.

homogeneous mixture

a mixture of two or more substances that are evenly distributed and which cannot be visually distinguished. (Mixture of sugar and water where the sugar is completely dissolved.)

heterogeneous mixture

a mixture of two or more substances that can still be seen as separate parts. (Mixture of salt and pepper.)

solute

a substance that is dissolved in a solution.

solvent

a substance that dissolves a solute in a solution.

solution

a homogeneous mixture formed when a solute is dissolved in a solvent.

protons, electrons, neutrons table

ion

when you change the number of electrons. There will be either a positive or negative charge. Charge is determined by the # of protons minus the number of electrons

cation

an ion with a positive charge

anion

an ion with a negative charge

isotope

an element with a different number of neutrons. An isotope is written with the symbol followed by a dash and the mass number. (Ex. Cl-37)

molar mass

the number on the Periodic Table with the unit ‘grams’ added to it.

Group 1

Alkali Metals

Group 2

Alkaline Earth Metals

Group 17

Halogens

Group 18

Noble gases

Melting point

The temperature at which a solid becomes a liquid.

Boiling point

The temperature at which a liquid becomes a gas.

Freezing point

The temperature at which a liquid becomes a solid.

Condensation point

The temperature at which a gas becomes a liquid.

Sublimation

The process in which a solid turns directly into a gas without passing through the liquid state.

Deposition

The process in which a gas turns directly into a solid without passing through the liquid state.

Vaporization

The process by which a liquid turns into a gas, occurring through boiling or evaporation.

Condensation

The process in which a gas turns into a liquid, typically when it loses heat.

Freezing

The process in which a liquid turns into a solid as it loses heat.

Melting

The process in which a solid turns into a liquid as it gains heat.