Unit A Chemistry PDF

UNIT A: CHEMISTRY  Chemistry WHAT IS IT? the branch of science that deals with the identification of the substances of which matter is composed; the investigation of their properties and the ways in which they interact, combine, and change; and the use of these...

UNIT A: CHEMISTRY  Chemistry WHAT IS IT? the branch of science that deals with the identification of the substances of which matter is composed; the investigation of their properties and the ways in which they interact, combine, and change; and the use of these processes to form new substances. 2  Terms You Should Know: ▸ Matter: A physical substance which has mass, and occupies space. ▸ Energy: Power derived from chemical or physical resources. ▸ State: A physical condition determined by molecular structure. 3  Physical Properties of Matter: 01 BOILING POINT/CONDENSATION POINT ✔ THE TEMPERATURE OF BOILING OR CONDENSING Pg. 13 of text 02 FREEZING POINT / MELTING POINT ✔ THE TEMPERATURE OF MELTING OR FREEZING 03 ✔ ABILITY TO BE BEATEN OR ROLLED INTO SHEETS MALLEABILITY WITHOUT CRUMBLING 04 DUCTILITY ✔ ABILITY TO BE STRETCHED WITHOUT BREAKING 4  Physical Properties of Matter: 05 STATE ✔ EXISTENCE AS A: SOLID, LIQUID, OR GAS 06 CRYSTAL FORMATION ✔ CRYSTALLINE APPEARANCE 07 MAGNETISM ✔ MAGNETIC ATTRACTION BETWEEN OBJECTS 08 CONDUCTIVITY ✔ ABILITY TO CONDUCT HEAT OR ELECTRICITY 5  Physical Properties of Matter: 09 SOLUBILITY ✔ ABILITY TO DISSOLVE 10 COLOR ✔ THE COLOR OF THE MATERIAL 6 7  Chemical Properties of Matter: 01 ABILITY TO BURN ✔ COMBUSTION (FLAME, HEAT, LIGHT) Pg. 13 of text 02 FLASH POINT ✔ TEMPERATURE NEEDED TO IGNITE A FLAME 03 BEHAVIOUR IN AIR ✔ TENDENCY TO DEGRADE, REACT, OR TARNISH 04 REACTION WITH WATER ✔ TENDENCY TO CORRODE OR DISSOLVE 8  Chemical Properties of Matter: 05 REACTION WITH ACIDS ✔ CORROSION, SOMETIMES BUBBLE FORMATION 06 REACTION WITH HEAT ✔ TENDENCY TO MELT OR DECOMPOSE ✔ RED- ACID ; BLUE- BASIC ; NO COLOR 07 REACTION TO RED/BLUE LITMUS CHANGE-NEUTRAL ✔ NOTE* colour change is considered a chemical property 9  Properties & Classification of Matter 10  Breaking it Down: Pure Substances ▸ Pure Substances: Contain only one type of particle and cannot be broken down into another substance by physical means ▹ Elements: Made up of one type of atom. (gold, oxygen, diamond etc) ▹ Compounds: Made up of more elements that are chemically combined in specific ratios. 11 (water, salt, crystals)  Breaking it Down: Mixtures ▸ Mixtures: Contain two or more pure substances. ▹ Homogenous: appear to be made of one substance and looks the same throughout (sugar & water mixed) ▹ Heterogeneous: Separate components are visible. Suspension: A mixture in which particles are dispersed throughout a fluid. (sand & water) Colloid: Particles that are suspended and cannot be filtered apart easily. They look like one substance. (gelatin, milk) 12  Matter can CHANGE! New Composition material of with substance different stays the properties same than original irreversible reversible 13  Identifying Chemical Reactions ▸ All chemical reactions are characterized by: ▹ the formation of a new substance with new physical and chemical properties ▹ the release or absorption of energy. 14  Check & reflect Pg. 17 # 1, 3-9, 11 15 Developing Ideas About Matter  Ancient Chemistry Metallurgy - science of producing and using metals The process of heating copper before it’s hammered ot make it stronger and less brittle is called annealing. The process of separating metals from compounds by melting them is called smelting. 17  Food Chemistry The development of food preservation techniques was necessary for human survival and has been known for thousands of years. - cooking, freezing, drying, salting, smoking, spicing, fermenting etc. 18 19  Atomic Theory Begins on page 20 in text 20  Idea 1: Spontaneous Generation ▸ Who: Greek philosopher Aristotle ▸ The idea that living things can be generated out of non-living material. ▹ “Pneuma” = vital heat ▹ “Anima” = soul ▸ Used to try and explain the “spontaneous” appearance of maggots and flies on meat. 21 22  Idea 2: The Billiard Ball Model ▸ Who: John Dalton ▸ He believed that matter possessed the following characteristics: ▹ All elements are made up of atoms ▹ Atoms of the same element are identical ▹ Atoms are indivisible ▹ Atoms combined in fixed ratios to form compounds. 23 ▸  Idea 3: The Raisin Bun Model ▸ Who: J.J. Thompson ▸ He believed that matter possessed the following characteristics: ▹ Atoms have one large positive charge ▹ Small negative charges are embedded in the positive particle ▸ His experiments showed the existence of positive and negative particles. 24 ▹ P. 22 figure A1.15  Idea 4: The Planetary Model ▸ Who: Ernest Rutherford ▸ He believed that every atom is very tiny, and has an extremely small, dense positively charged core called the nucleus ▸ The negative e-’s orbit the nucleus like planets around the sun. 25 ➤ Rutherford conducted an experiment in which he shot high speed particles through a sheet of gold foil ➤ The particles did not go straight through the gold foil, from which he deduced that each atom must have a small dense, positively charged nucleus. 26  Idea 5: The Bohr Model ▸ Who: Niels Bohr ▸ He thought that electrons were arranged around the nucleus in very specific orbits or energy levels ▸ The e-’s had a very specific orbits which he deemed as energy levels. 27  Bohr’s Ideas Come to Light ▸ Bohr used the light emitted from excited Hydrogen atoms to form his ideas about the structure of the atom ▸ Light is emitted when an electron (e-) falls from a higher energy level to a lower one. A different colour is emitted for each different transition. ▸ Bohr reasoned that this means electrons can only exist in specific locations 28  Idea 6: The Quantum Mechanical Model ▸ The modern model of the atom described the positions for the e-’s in an atom in terms of mathematical probabilities. ▸ An e- can potentially be found at any distance from the nucleus but tends to exist more frequently in certain regions around the nucleus than others, depending on its energy level. 29  Check & reflect Pg. 25 # 1, 4-8 30