Download Matter and Its Changes (Chapter 1)

Chapter 1 Activities of Science
Observation - qualitative (senses) and quantitative (measurement) of
the properties of an object or system.
Warning!: Since observation depends on what one already knows there is a possibility that you can “observe”, even if it does
not happen. (Sometimes referred to as ‘wishful thinking”.)
Remedy - multiple repetitions of the same experiment by more than
one person
Interpretation (inference) - to understand, or explain the meaning of
something
Classification - grouping items according to like characteristics
(regularities)
Hypothesis - a temporary “explanation” for an observed regularity.
Must be testable
Theory - when a hypothesis has been tested many times leading to a
high degree for confidence. A theory accounts for past
events and accurately predicts future ones
Model - a representation intended to convey information about
another object or event
*Neutered Ned
* Bohr Model
Chemistry - the branch of science concerned with properties,
composition and behavior of matter
Matter - anything that has mass and occupies space
Mass - gives matter the property of weight and inertia
Inertia - resistance to change in the motion of an object
(stop, start, change direction)
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Question:
Is the glass empty?
- Syringe test
Question:
Does light have mass?
- does not respond as does air
- wave/particle duality
-hard to say
- for this course “no” but in Physics
Matter is conserved
- during a reaction, matter cannot be created or destroyed only its form can be changed.
Match (mass) = match burned (mass) + _________ + E
heat/light
smoke (CO2 + H2O)
E = energy - no matter which can cause a change in matter
E = mc2
(energy) (mass)
Energy is conserved
- during an energy conversion, there is no loss or gain of
energy; however, some may become unusable, but not lost.
Diagram
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Four Physical States of Matter
solid
atoms locked into pattern
liquid
atoms close but can move past each other
gas
atoms fa apart, move in straight lines
with elastic collisions
plasma protons and electrons are stripped from
nuclei; matter exists as charged particles
Potential Energy
- the energy of position due to gravity…consider the ‘stored energy’ in
the roller coaster car.
- the energy of ‘being’ - more correctly, the energy tied up in chemical
bonds…consider the energy released from burning gasoline.
C8H18 + O2 ---> CO2 + H2O + ENERGY
* describe the potential energy of a flower
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Kinetic Energy
- the energy of “motion” or work.
Kinetic energy = ½ (mass) (velocity)2
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