Unt 2: Matter and Phase Changes

Physical property

Describes the physical characteristics of the substance

Physical property examples

State of matter, texture, odor, color, appearance, hardness, density, melting, freezing and boiling point, solubility, and viscocity (how it flows)

Chemical property

Describes how the substance reacts with other substances

Chemical property examples

Reactivity, toxicity, ph, conductivity, flammability, corrosiveness, if it rust easily

Physical Change

Matter changes form but not its chemical identity

Physical Changes Examples

phase changes (melting, boiling, freezing), bending/cutting, breaking, dissolving/absorbing, chopping wood, mixing gray and green marbles

Chemical Changes

a chemical reaction occurs and new products are formed

Chemical Changes examples

Burning wood, rotting banana, fireworks, and mixing vinegar and baking soda

Pure substances

Type of matter with a fixed or definite composition that cannot be separated by physical processes

Element

Sample of matter composed of atoms of the same element

Element examples

carbon, Br2, N, H2

Compound

Sample of matter composed of molecules of more than one element

Compound examples

CO2, NaCl, H2O

Molecules

- A molecule is two or more atoms connected by chemical bonds, which form the smallest unit of a substance that retains the composition and properties of that substance.

- A molecule consists of two or more atoms of the same element, or different elements, that are chemically bound together.

The relationship between molecules and compounds

All compounds are molecules but not all molecules are compounds

Mixtures

A type of matter that consists of 2 or more substances that are physically mixed, but are not chemically combined

Homogenous mixture

A mixture of 2 or more substances so that the composition is the same (uniform) throughout

Homogenous mixture examples

Coffee, tomato soup, air

Heterogeneous mixture

Mixture of 2 or more substances so that there is separation and does not contain the same composition throughout

Heterogeneous mixture examples

Salad, trail mix

Filtration

A separation technique carried out by pouring mixture into a funnel with filter paper in it where the filtrate (liquid) is collected into a flask leaving the residue in the filter paper

Paper Chromotography

A separation technique carried out by putting paper in a solvent like water and Etoh (alcohol) and the substance (ink) is being separated, moving up the paper by capillary action. The results is the colors separating because of its different polarities

Distillation

Separation technique carried out by heating the solution until the first substance boils and goes to the gaseous state then gets cooled down through the tube to a another flask while the other mixture stays. This separation works based on their different boiling points

Properties of metal

Lustrous, conductive, malleable, ductile, reactive

Properties of Nonmetal

dull, brittle, poor nonconductive, not reactive, not ductile

Properties of Metalloids'

properties of both metals and nonmetals: semi conductive, lustrious to semi lustrous, brittle; metalloids can react with other elements. The reactivity of metalloids depends on the specific metalloid and the element it is reacting with

Sections of the Periodic Table

18 family or groups (vertical columns)

Group 1 = alkali metals

Group 2 = alkaline earth metals

Groups 3-12 = transition elements

Group 17 = halogens

Group 18 = noble gases or inert elements

Inner transition metals/Rare earth elements/inner earth elements

- Lanthanides = elements 57-71

- Actinides = elements 89-103

Characteristics of liquids

- Definite volume

- no definite shape, so they are fluids

- their particles spread out but there still contained

- medium, slow motion of particles

- repel each other, and weak attractive forces

- little space between the particles, they are near each other

Characteristics of Solids

- definite volume and shape

- the particles are so tightly together that they are vibrating

- strong attractive forces, stick together

- little to no space between particles;

- the arrangement of particles is boxy

Characteristics of gas

- They are fluids

- Particles spread out, fast in all different directions

- No attractive forces, they repel each other

- Far apart, lots of space between the particles

Phase Change: Melting

Solid to liquid; Energy absorbed

Phase Change: Sublimation

Solid to gas; Energy absorbed

Phase Change: Freezing

Liquid to solid; Energy released

Phase Change: Evaporation/Boiling

Liquid to gas; Energy absorbed

Phase Change: Condensation

Gas to liquid; Energy released

Phase Change: Deposition

Gas to solid; Energy released

Kinetic energy (KE)

energy of motion/movement

Relationship between KE and heat

When heat added (adding energy), the particles move faster and the KE increases

Potential Energy (PE)

stored energy

State of matter and PE

Solids have the highest PE and gases have the lowest

Heat Diagram of Water

Used to show how the temperature of a certain amount of water changes as heat is added constantly.

What happens in a Heat Diagram of Water: "A" section

At a solid, temp is increasing

KE is increasing

What happens in a Heat Diagram of Water: "B" section

Water changes from solid to liquid

Solid+ liquid temp is staying the same, meaning the melting point

What happens in a Heat Diagram of Water: "C" section

At a liquid, temp is increasing

KE is increasing

phase diagram

The phase diagram of any solution is a representation of the various pressure and temperature combinations that create each phase. The three phases are solid, liquid and gas. Changing the pressure at a certain temperature can lead to a change in phase.