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What is Chemistry?
Natural Sciences
Chemistry -
Study of composition, structure, and properties of substances and the changes they undergo
Biological Sciences
• Concerned with living things
Physical Sciences
• Non-living things
• CHEMISTRY!!
What is Chemistry?
Chemistry Study of the composition, structure, and
properties of matter and the changes it undergoes Chemical
Any substance that has a specific composition Examples – sucrose, carbon dioxide, water
Branches of Chemistry Organic
Study of substances containing carbon Inorganic
Study of substances that do not contain carbon Physical
Study of interrelationships between energy and matter Biochemistry
Study of processes that occur in living things Analytical
Identification of substances and determination of the composition Theoretical
Uses math and computers to explain and make predictions
Types of Research
Basic Research Increasing knowledge How? Why?
Applied Solve a problem
Technological Development Production and use of products that improve our
quality of life
Basic Building Blocks of Matter
Atom Smallest unit of an element that maintains the properties of
that element Smallest “piece” of matter
Element A pure substance made up of only one kind of atom
Weight Measure of the Earth’s gravitational pull for matter Use a scale
Mass Measure of the amount of matter in a substance Use a balance
Basic Building Blocks of Matter
Matter Anything that has mass and takes up space
Inertia Resistance to change in motion
Law of Conservation of Mass Matter cannot be created or destroyed in ordinary
chemical reactions
Properties
Extensive property Depends on the amount of matter Volume, mass, shape, state
Intensive property Does NOT depend on amount of matter Density, melting point, boiling point
Properties
Physical property Can be observed or measured without
altering identity of substance Color, weight
Physical change Any change that does NOT change identity
of substance Melting, cutting wire
Properties Change of state
Physical change from one state to another States of matter
Solid Definite volume, definite shape; closely packed Rotational motion of particles
Liquid Definite volume, indefinite shape; Not as closely packed Rotational and Vibrational motion
Gas Indefinite volume and shape; Widely spaced particles Rotational, Vibrational and Translational motion
Plasma High temperature state in which atoms lose electrons http://public.lanl.gov/alp/plasma/ubiquitous.html
Properties
Chemical property Ability of a substance to undergo a change that alters its
identity
Chemical change A change in which new, different substance are formed (a
change to its identity) Reactant
Substances that undergo a change Product
Substances that are formed Reactants Products
Evidence of a chemical change Test products
Only way to have proof! Gives of heat and/or light
Chemiluminescence – gives off light Start video at 1:15
Exothermic Rxn – gives off heat
Endothermic Rxn – takes in heat
Production of a gas (bubbles) Formation of a precipitate
Precipitate – a solid that separates from solution
Quiz
http://www.quia.com/quiz/303980.html Demos
Hot/Cold Packs Vinegar/Baking Soda “Beverage” simulation Chemiluminescence Stop Light Reaction Oscillating Color
Energy
Ability to cause change or ability to do work Examples – chemical, electrical, mechanical,
sound, thermal, light, and more… Classification
Kinetic Energy of motion
Potential Stored energy
Energy
Law of Conservation of Energy Energy can be converted from one form to
another; cannot be created or destroyed Law of Conservation of Mass (matter) and
Energy Matter and energy cannot be created or
destroyed
Classification of Matter Two types of matter
Mixture – blend of 2 or more kinds of matter; each keeps own properties; can be separated physically Heterogeneous – not uniform throughout
Salt and pepper, pizza, granite Homogeneous – uniform in composition; solution
Salt water
Pure substance – same composition; cannot be separated by physical means (you lose all original properties when separating) Element – cannot be decomposed by ordinary change
Au, Fe, Na Compound – can be decomposed into 2 or more simpler
substances - chemically H2O, sugar
Matter
Law of Definite Composition A chemical compound contains the same
elements in exactly the same proportion by mass regardless of size
Elements
They are the building blocks of matter They are organized on the Periodic Table Group/Family
Vertical columns (1-18) Elements very similar to each other in a family
Period Horizontal rows (1-7)
Elements
Types of elements Metals
Left side of Periodic Table Good conductor or heat/electricity, luster, ductile, malleable
Nonmetals Right side of table Poor conductor Noble Gases – group 18, non-reactive, very stable
Metalloids Along step ladder Semiconductors – Si, Ge
Elements
KNOW THE COMMON ELEMENT NAMES AND SYMBOLS!!! THESE WILL NOT GO AWAY. YOU ARE GOING TO NEED THEM ALL YEAR LONG!!!