Chemistry - States of Matter, Phase Change, Elements, Compounds, and Mixtures

Solids

• form of matter that has a definite shape and volume

• shape of solid doesn’t depend on the shape of its container

• particles in a solid are packed tightly together and orderly arranged

• solids are almost incompressible (difficult to squeeze into a smaller volume)

• solids expand only slightly when heated

Liquids

• particles are in close contact, but are not orderly arranged

• particles in a liquid are free to flow —> liquids take the shape of its container

• volume of a liquid is fixed/constant

• almost incompressible

• tend to expand slightly when heated

Gases

• take both the shape and volume of its container

• particles in a gas are much farther apart than the particles in a liquid

• the space between particles allow gases to be easily compressed into smaller volumes

What is happening in letter A?

• the water is a solid (ice)

• temperature is increasing

What is happening in letter B?

• melting is occurring

• ice and liquid water are present

• temperature remains the same

What is happening in letter C?

• the water is a liquid

• temperature is rising again

What is happening in letter D?

• vaporization is occurring

• liquid water and water vapor are present

• temperature is constant

What is happening in letter E?

• the water is a vapor

• temperature is increasing

What is happening in number 1?

• substance is a gas

• temperature is decreasing

What is happening in number 2?

• condensation is occurring

• gas and liquid are present

• temperature remains constant

What is happening in number 3?

• substance is a liquid

• temperature continues to decrease

What is happening in number 4?

• freezing is occurring

• liquid and solid are present

• temperature is constant

What is happening in number 5?

• substance is a solid

• temperature decreases

Melting

• solid turns into a liquid

Condensation

• gas turns into a liquid

Deposition

• gas turns into a solid

• rarely happens

Freezing

• liquids turns into a solid

Sublimation

• solid turns into a gas

• rarely happens

Vaporization

• liquid turns into a gas

Elements

• shown on the periodic table by a symbol

• always 1 or 2 letters

• never more than 1 capital letter

• pure substance

• cannot be broken down by physical change or chemical change

• made up of only 1 type of atom

Compounds

• represented by a formula

• at least two different element symbols

• always more than 1 capital letter per formula

• pure substance

• form when two or more different elements bond together chemically

• can be separated only by a chemical change

• always exists as a molecule

Mixtures

• not always the same concentration

• form when elements and/or compounds are combined physically

• can be separated by physical change

• not a pure substance

Homogenous Mixture

• particles are evenly distributed throughout the mixture

Heterogenous Mixture

• particles are not evenly distributed throughout the mixture

Flotation

• useful for separating mixtures that are composed of parts that have different densities 

Sifting

• involves a tool called a sieve

• the sieve has holes that allow smaller materials—but not larger materials—to pass through

• useful for mixtures composed of particles with different sizes

Magnet

• useful for separating mixtures that contain magnetic and non-magnetic parts

Filtration

• useful for separating a mixture that contains liquid and solid parts as well as mixtures that contain particles with different sizes 

Distillation

• a solution is heated until the solvent vaporizes

• the solute does not change state and is left behind

• useful for mixtures that contain parts with different boiling points

Panning

• helps miners separate gold from sand and gravel

• miners scoop up material from the stream bed and swirl it in a metal pan

• useful for mixtures that are composed of particles with different sizes

Chromatography

• useful for mixtures that contain parts that have a difference in solubility 

Molecules

• two or more atoms combine or bond

Subscripts

• indicate the number of each atom present in a molecule

Coefficients

• indicate the number of molecules or atoms involved in a reaction