Science 9 Unit 2: Chemistry
What is Chemistry?
Chemistry: The study of the composition, properties, and reactions of matter
Chemistry: Definition The study of the composition, properties, and reactions of matter Matter: Anything that has mass and takes up space
Chemistry: Definition The study of the composition, properties, and reactions of matter Matter: Anything that has mass and takes up space everything in our universe except forms of energy (heat, light, electricity, radiation and sound)
Properties of Matter Matter has Physical and Chemical properties
Physical Properties of Matter Properties that can be observed or measured without changing a substance Ex. colour, malleability, conductivity, magnetism, luster, density, texture, melting/ boiling points Iron: Shiny, grey, magnetic
Chemical Properties of Matter Properties observed only when one substance reacts with another Ex. Combustibility (burning), reactivity, toxicity rust Iron: reacts with oxygen to form
Chemistry Around Us
Chemistry Around Us H 2 0
Chemistry Around Us Chemicals may be: Natural or man-made Safe or potentially dangerous
Safety To use chemicals safely we need to: be aware of their chemical properties be aware of necessary precautions we should use when handling them
WHMIS WHMIS: Workplace Hazardous Materials Information System Canada-wide system designed to give employers and workers information about hazardous materials used in the workplace.
WHMIS There are 3 ways information on hazardous materials is provided: 1.labels on the containers 2.material safety data sheets (MSDS) with detailed information 3.worker education programs.
WHMIS Labels *All controlled products must have WHMIS labels Label includes: Name of the chemical The WHMIS hazard symbols Risks and precautions First Aid instructions Supplier s name and address A reference to the matching MSDS (with more information)
WHMIS Symbols Compressed Gas Gas under pressure Heat may cause contents to explode May explode if dropped
WHMIS Symbols Flammable and Combustable May catch fire or explode in the presence of a spark or open flame Flammables burn sooner and at lower temperature than combustibles
WHMIS Symbols Oxidizing increase the risk of fire if they come in contact with flammable or combustible materials
WHMIS Symbols Dangerously Reactive Very unstable May explode from shock, friction or increased temperature May react with water to produce toxic gas
WHMIS Symbols Corrosive Cause skin and eye irritation Tissue damage May eat through metals
WHMIS Symbols Poisonous and Infectious (Causing Immiediate and Serious Effects) May be fatal if inhale, swallowed or absorbed through skin
WHMIS Symbols Poisonous and Infectious (Causing Other Toxic Effects) Poisonous upon repeated exposure Can cause cancer, birth defects etc
WHMIS Symbols Biohazardous contain harmful microorganisms May cause disease
WHMIS Recall There are 3 ways information on hazardous materials is provided: 1.labels on the containers 2.material safety data sheets (MSDS) with detailed information 3.worker education programs.
General Lab Safety Read entire lab procedure before beginning Listen to teacher instructions Long hair should be tied back Lab coats and safety glasses should be worn If anything is broken or anyone is injured, notify the teacher No food, drink, or gum in the lab
Atomic Theory In science the terms law and theory have different meanings than they do in everyday language Think about what comes to mind when you hear these terms and write your own definition in the table provided
Atomic Theory Scientific Definitions: Theory Explanation of events, patterns, or relationships that have been observed over and over again How it happens Law Description of observations that are supported by reliable evidence What happens
Atomic Theory
Atomic Theory https://www.youtube.com/watch?v=gyn2rhbhieu
Atomic Theory Recall: Chemistry is the study of matter (it s composition, properties, and reactions) To understand chemistry we must first understand matter
Atomic Theory Recall: Chemistry is the study of matter (it s composition, properties, and reactions) To understand chemistry we must first understand matter Atomic Theory includes the various descriptions of matter and how it behaves
Atomic Theory Atomic theory has evolved over hundreds of years Use your text book and worksheet to summarize the contributions of early scientists to our understanding of matter Pages 24-28
Atomic Theory Democritus First to suggest the smallest piece that you could divide something into is an atom Dalton: billiard ball model atom is the same throughout and is indivisible Thomson: raisin bun model negative electrons scattered throughout a positive area of the atom
Atomic Theory Rutherford: planetary model electrons circling the center of the atom proposed that the atom is mainly empty space with very small and heavy nucleus Bohr: orbital model electrons circling the nucleus at different energy levels away from the nucleus
Atoms Atom the smallest particle of an element that retains the properties of that element made up of subatomic particles called protons, neutrons, and electrons
Atomic Structure Atoms contain 3 types of sub atomic particles Subatomic Particle Symbol Charge Mass (amu) Location Proton p+ + 1 Nucleus Neutron n 0 1 Nucleus Electron e- - 0 Outside of nucleus in energy levels
Atomic Structure Protons and neutrons are inside the nucleus (centre) The electrons are arranged outside of the nucleus in levels The number of protons and number of electrons are equal so that charges balance