1. Mixtures of Matter What does the Law of Conservation say about matter?

2. Classification of Matter Matter Mixtures Pure Substances Heterogeneous Homogeneous Elements Compounds Mixtures

3. Matter is makes up everything around us. Mixtures are combinations of two or more pure substances in which each pure substances retains its individual chemical properties. Pure substances are matter that is uniform and unchanging in composition.

4. Mixtures are divided into two types. Heterogeneous – mixtures that do not blend well and individual substances remain distinct Homogeneous- mixtures that have a consistent composition throughout Categorize the mixtures: Lemonadesaltwaterorange juice

5. Solutions are homogeneous. They can be formed by solids liquids or gases. Gas – Gas Air is a mixture of 70% Nitrogen, oxygen and argon gas with traces of many other gases. Gas – Liquid Soda contains carbon dioxide gas in solution. Liquid – Gas Fog Liquid – Liquid Vinegar is acetic acid and water. Peroxide is usually a dilute solution that includes water. Solid – Liquid Kool-aid and Crystal light powder in solution. Solid – Solid Steel is a alloy of iron ore and carbon. Alloys are mixtures of two or more metals.

6. Separation of Mixtures Separating some mixtures is much easier than separating other mixtures. Separating a heterogeneous mixture like iron fillings and sand is easier than separating a nickel. Techniques: Filtration – using filters Distillation - heating Crystallization – separation where a solid is separated producing highly concentrated pure substance Chromatography – separation of ink by density

7. Atomic Theory Democritus – 460-370 BC – philosopher - Atomos – named the atom Aristotle – 384-322 BC – philosopher – denied the existence of atoms and did not believe in the nothingness of space – developed the idea of categorizing nature by animal, plant or mineral

8. Dalton – 1766-1844 – teacher and scientist – All matter composed of atoms. Atoms of elements are all the same size and mass and are specific to that element. Atoms cannot be created, destroyed or divided. Different atoms combine to in specific ratios to make specific compounds. In a reaction, atoms are separated, combined or rearranged.

9. Crookes – 1873 – developed the cathode ray tube that led to the development of the modern TV – research conducted with the tube helped scientist understand the presence of streams of particles that were negatively charged and glowed at different colors with different gases https://en.wikipedia.org/wiki/Cathode_ray

10. JJ Thomson – 1856 -1940 –English physicist – Used the cathode tube to measure the mass of the particles and truly the first particle of the atom, the electron – Developed the plum pudding model of the atom

11. Robert Milikan – 1868-1953 – determined the charge of the electron within 1% of today’s accepted value with his oil drop experiment

12. Ernest Rutherford- 1911 – discovered the existence of a nucleus with the gold foil experiment – also located the proton and charge James Chadwick- 1932 – fellow scientist of Rutherford identified the neutron and its mass

13. Isotopes Isotopes are atoms with the same number of protons but have different number of neutrons. Isotopes differ in mass because neutrons lend a significant amount of mass to the atom. The atomic mass numbers on the periodic table are a combination and average of the isotope of an atom. EX – Potassium- 39 Potassium – 40 Potassium - 41

14. namesymbol e -P+n° HydrogenH111-1=0 HeliumHe224-2= LithiumLi337-3= BerylliumBe44 BoronB55 CarbonC66 PotassiumK77 ChromiumCr24 ZirconiumZr40