introduction to chemistry. chemistry defined a.studies matter, its properties and its interactions...
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Introduction to ChemistryIntroduction to Chemistry
Chemistry definedA. Studies matter, its
properties and its interactions
B. A physical science
C. Ties other sciences (Physics and Biology) together
Matter defined
Anything that:A. Has volumeB. Has massC. Uses energy
What do these mean?
Matter has Volume
A. The amount of space a piece of matter occupies
B. 3 dimensional (L x W x H)
Matter has MassA. The amount of matter present in an object
(even if the object is too small to be seen). “How much ‘stuff’ is present”
B. The amount present is determined by the object’s INERTIA
C. Inertia: an object’s resistance to a change in its motion, speed, direction, or position. The more an object resists changes, the more inertia it has and therefore, the more mass is present
Mass WeightA. Weight depends on
gravity and the distance from the center of the earth
B. Is a “downward” pulling force
C. What ever goes up, must come down
Not so with mass.
Matter uses Energy: The ability to do workTypes of EnergyA.Kinetic: motionB.Potential: positionC.Chemical: ionic and covalent bonds within
compounds holding different atoms togetherD.Thermal: heat (friction)E. Radiant/Solar: lightF. Electricity: moving electronsG.Nuclear: energy holding the nucleus of an atom
together
Matter and EnergyLaws of Conservation of Matter and EnergyA.1st Law: Matter and energy cannot be created
or destroyed but can be transformed into each other. So matter and energy are interchangeable
B.2nd Law: With each transformation, some of the total amount is transformed into heat. Heat cannot be recovered/recycled. It is considered “lost” (although it’s still there) and can’t be used again (transformed).
How matter uses energyMatter uses energy to change physical formA. Solid (least energy, all particles connected in all
directions)B. Liquid (“medium” energy, particles connected to form
“layers”) C. Gas (most energy, no connections between particles)D.Vapors are the gaseous form of something that is
usually a solid or liquid at room temp (ex. Humidity = water vapor)
How do these changes happen?
Solid
Liquid
Gas
Melting
Boiling
Sublimation
Condensing
Depositing
Freezing
Properties of MatterMatter is classified based on its properties. Not possessing a property is also
important to note. There are 2 kinds of properties: physical and chemical
Physical PropertiesA. can be observed without changing the identity of the matter
being studiedB. Can be reversed if it alters only the appearance
Example: melting ice freezing waterC. Two kinds: EXTENSIVE and INTENSIVE
Extensive properties: based on amount of matter present. A property that’s measured. Ex. Mass, length, volume Intensive properties: fundamental to matter regardless of amount. Ex. Gold always has the same color whether it’s a bar of gold or gold foil
Examples of Physical properties• Color• Odor• physical state• density • magnetic ability • conducting energy flow • insulating against energy
flow
• malleability (can be hammered into foils)
• ductility (can be pulled into wires)
• specific heat (how fast something warms up)
• Solubility (ability to dissolve)
And there are many others!
Physical Changes in Matter
A. Only change the physical appearance in matter (size, shape)
B. Does not change the identity of the matter
Examples• Filtering• Crystallizing• Boiling/condensing• Melting/freezing• Dissolving• Decanting• Tearing/cutting
And there are many others!
Chemical Properties and Changes of Matter
A. Can only be observed during changes in the matter’s identity
B. Changes the matter into a different substance
C. Chemical changes are called REACTIONS and ALWAYS involves energy being transferred between the original matter to the new matter
Examples• Ability to burn• Supporting burning• Fizzing• Tarnishing/rusting • Toxicity• Decomposition/rotting• Digestion• PhotosynthesisAnd there are many others!
Classifications of Matter• Several different methods – helps to understand matter• Based on physical observations first, then chemical
observationsTermsA. Mixture: Combination of 2 or more substances and can be
physically separatedB. Pure substance: Any material that can not be broken down
any further C. Heterogeneous: Composed of unlike materials or substancesD. Homogeneous: Composed of like materials or substancesE. Element: Any substance that cannot be broken down any
further by chemical means F. Compound: Substance containing 2 or more elements
chemically combinedG. Solution: A homogeneous mixture in liquid form
Matter
Mixtures Pure Substances
Heterogeneous
Compound Element
Homogeneous
Solution
Matter
Heterogeneous Homogeneous
Solution Pure Substance
Element Compound
Other ClassificationsFor compounds• Organic: carbon based, carbon present in the
molecule (all living things are considered this)• Inorganic: no carbon, or carbon present but not
most importantFor elements• Metal: good conductors of energy, esp. heat,
malleable, ductile• Nonmetal: good insulators (do not conduct
energy), never malleable, never ductile• Metalloid: some metal properties, some nonmetal
properties
Introduction to the Periodic Table (PT)
A. Family/Group – similar properties and atomic structures; columns
B. Period – increasing atomic number; rows Na
11
22.99
Atomic Number (identity)
Atomic Mass
Element Symbol
Family 1: Alkali MetalsFamily 2: Alkali Earth MetalsFamily 3: BoronFamily 4: CarbonFamily 5: NitrogenFamily 6: OxygenFamily 7: HalogenFamily 8: Noble Gases (most stable)Middle Section: Transition MetalsBottom Section: Rare Earth Metals
The Modern Periodic Table
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