Matter: Properties, Changes & Classification

Solid, Liquid, Gas Elements, Mixture, Compound Particle Diagrams Homogeneous vs. Heterogeneous Mixtures Separation of Mixtures ● Filtration ● Evaporation ● Distillation Physical and Chemical Properties and Changes Intensive and Extensive Properties Law of multiple proportions Law of constant composition Law of conservation of mass

chemistry

the study of matter and its changes

chemical

a substance that always has the same composition and properties wherever it is found

e.g) water (H₂O), salt (NaCl), sugar (C₆H₁₂O₆)

matter

has mass and takes up space (volume)

made of atoms

atom

the smallest part of a substance that cannot be broken down chemically

made up of subatomic particles

1. proton

2. neutron

3. electron

element

made of one single type of atom only.

cannot be broken down into simpler chemical substances by ordinary means.

ionic bond

transfers electrons

between metal & nonmetal

e.g) NaCl = ionic

• sodium is a metal

• chlorine is a nonmetal 

covalent bond

shares electrons

between two non metals

e.g ) H₂O = covalent

• hydrogen is a nonmetal 

• oxygen is a nonmetal

compound

two or more different elements chemically combined in a fixed ratio

e.g) H₂O (water), C₁₂H₂₂O₁₁ (sugar), CO₂ (carbon dioxide)

molecule

a group of atoms covalently bonded together 

• can be all different or same element 

• nonmetals 

e.g) Ozone (O₃), water) H₂O

molecule vs compound

a molecule is any group of two or more atoms bonded together, while a compound is a type of molecule that contains at least two different elements

pure substance

matter with constant composition.

pure substances = only one type of element or compound

mixtures

two or more substances mixed together but not chemically joined. 

proportions can vary.

• homogeneous

• heterogeneous

pure substance vs mixture

a pure substance has a fixed, uniform composition made of only one type of element or compound

while a mixture is a physical combination of two or more pure substances with a variable composition that can be separated by physical means.

homogeneous

one phase only.

parts of mixture are not distinguishable by naked eye.

• often aqueous (dissolved in liquid).

a combination of substances that are evenly distributed and uniform composition.

heterogenous

two or more phases.

components are not evenly distributed and remain physically separate.

parts distinguishable.

alloy

mixture of two or more metals, or a metal and one or more nonmetal.

• pure metal - single type of atom.

• substitutional - mixtures of metals where atoms of one metal replace atoms of another. 

• interstitial - in between spaces.

separation of mixtures

physical change is used to separate mixtures because there are no chemical interactions between the components.

filtration

the process of separating a mixture of a solid and a liquid.

evaporation

the process of heating the mixture to turn the liquid into a gas (vapor) to leave the solid behind.

distillation

separates a liquid mixture based on different boiling points.

chromatography

separate a mixture by different solubility in a solvent.

• solute = dissolved by solvent.

• solvent = dissolves the solute.

physical change

alters the appearance, form, or state of a substance without changing its chemical composition.

e.g) state, volume, temperature.

chemical change

changes that result in new substances with their own set of properties.

changes the chemical composition.

e.g) combustion, oxidation, decomposition.

physical properties

characteristics of a substance that can be observed without changing identity.

e.g) melting point, mass, color, dissolubility.

chemical properties

characteristics of a substance that can be observed only by changing chemical composition.

e.g) flammability, reactivity, acidity.

solid

definite volume.

holds its shape.

liquid

definite volume.

takes shape of container.

gas

indefinite volume (expandable/compressible).

takes shape of container.

intensive properties

depend on the type of substance, not on the amount of it

e.g) density, boiling point, color

extensive properties

dependent upon the amount of substance given

e.g) mass, length, energy 

law of conservation of matter

matter can neither be created nor destroyed, only changed in form, through chemical or physical changes

law of definite proportions

a given compound will always contain exactly the same proportions of element by mass.

e.g) H₂O is always 11% hydrogen and 89% oxygen by mass.

law of multiple proportions 

when different compounds are formed by a combination of the same elements, different masses of one element combine with the same fixed mass of the other in a ratio of small whole numbers.

e.g) CO (carbon monoxide) 12 grams of carbon and 16 grams of oxygen

CO₂ (carbon dioxide) 12 grams of carbon and 32 grams of oxygen

oxygen mass ratio - 16:32 = 1:2