MATTER : matter can be classified into mixtures, solutions, elements and compounds.

Any amount of each substance is ok. Most mixtures can be separated physically by: magnets, evaporation, filtration, or centrifuge, and distillation. They keep their own properties. They can change physically. Matter that consists of 2 or more substances that are NOT chemically combined. They are Physically Combined

TYPES OF MIXTURES HETEROGENEOUS: Not well mixed; Does not appear the same throughout. Will separate upon standing. Particles are large, and can be seen. Ex: concrete, oil and vinegar; cereal and bananas; salad, BLT; PB&J HOMOGENEOUS Two or more substances evenly mixed. You can NOT see the different substances, even with a microscope! Examples: gatorade, salt water, brass, air

Heterogeneous mixtures A type of mixture where two or more substances are not evenly mixed. You can see with your eyes the different parts that make up the mixture. The particles are insoluble. This means the particles do NOT dissolve. Only scatter throughout when shaken. *Often cloudy Scatter light(Tyndall Effect)

Mixture that is EVENLY mixed. Appears the same throughout Particles are very small, and sometimes dissolved. Solutions Also known as Solutions — have 2 parts to them: solute and solvent Solute —substance that dissolves (ex. Salt, sugar) Solvent —substance that does the dissolving ( ex: water) (Water is called the Universal solvent!) o Particles are dissolved in a solution. o Solutions do Not scatter light o They often appear clear o 1 substance dissolves in another.

Solute and solvent

Key terms about solutions: Soluble: a substance can dissolve in another substance (salt) Insoluble: Substance can NOT dissolve in another substance (pepper, oil) Solubility : Amt. of solute that can completely dissolve in a specific amt. of solvent at a given temperature. (Salt water) Saturated: all the solute that can be dissolved in a specific amt of solvent at a given temp. – can’t absorb any more. Alloy: Metal solutions that are Solids dissolved in solids— Brass: copper and Zinc Gold: gold and copper

The tyndall effect

EXAMPLES OF COLLOIDS: Fog= liquid in gas Butter= liquid in solid Smoke=liquid in gas Mayo= liquid in liquid

HOW ARE ELEMENTS DIFFERENT FROM MIXTURES? When all particles are alike, it is a pure substance. Elements- simplest pure substance; there are MORE THAN 113 elements; they Began to be discovered in the 1940’s. Atom- smallest particle of an element that has all the properties of that element.

SO WHAT ARE COMPOUNDS AND MOLECULES, THEN? Compound- 2 or more different elements chemically combined ex. H 2 O, NaCl Molecules- 2 or more atoms chemically combined. ex. H 2, H 2 O, N 2

ElementsCompoundsMixtures Made up of only 1 kind of atom. Made up of more than 1 kind of atom. Made up of more than 1 kind of molecule. Can’t be broken down by chemical means. Can be broken down by chemical means. Can be separated by physical means. Have same properties as atoms making it up. Have different properties from elements making it up. Have same properties as substances making them up. Have same properties throughout. Have different properties throughout.

Chemical Symbols- shorthand way to represent elements. ex. C, H, Na (sodium) Ca, Cl Chemical Formula- combinations of chemical symbols ex. H 2 O Subscript- tells the number of atoms in a compound ex. H 2 O CO 2 Coefficient- tells the number of molecules ex. 2H 2 O Chemical Equation- describes the chemical reaction using symbols and formulas

STRUCTURE OF AN ATOM !!!!! WHAT IS INSIDE AN ATOM????

THE PLAYERS: 3 major subatomic particles: Proton- positively charged, 1 AMU, inside the nucleus, determines the element Neutron- no charge, 1 AMU, inside the nucleus. Electron-negatively charged, 1/1836 AMU, outside the nucleus on energy shells and energy levels. AMU= ATOMIC MASS UNIT– (THEIR MASS!!)

HOW DO WE WORK WITH ATOMS AND ELEMENTS????? Atomic #--# of protons of an element. It identifies the element. A # = # P Mass # - This is the # that is = to the # of protons and the neutrons in the nucleus. m# = P + N NEUTRAL ATOM: # E = # P Atomic Mass (weight) -- the average mass # of all of the isotopes of an element

BUT WHAT IS THE NUMBER UNDERNEATH THEM ON THE PERIODIC TABLE??? Isotopes—These are when an element has its regular # of protons, but a different # of neutrons. Isotopes of an element are that element, with a different # of neutrons. ex: H-3, U-238.