Ex:
*Notice: the number of protons on the left equals the number
on the right! total mass units on the left equals total mass units
on the right!
2 types of nuclear reactions:
1) fusion: 2 hydrogen at
Ch. 2 Energy & Matter
energy: the capacity to do work or to produce heat
work: the capacity to move an object over a distance
against a resisting force
W=Fxd
3 main categories of energy:
1) kinetic en
2-4: Elements & Compounds
element: a substance that cannot be
separated into simpler substances by a
chemical change
- element abbreviations are one or
two letters
- names after people, places; some
h
3-2: Discovering Atomic Structure
Faraday: thought atomic structure related to
electricity (1839)
*Atoms contain particles that have electrical
charge!
Benjamin Franklin:
-two kinds of charges (+) and
1-7: Dimensional
Analysis
dimensional analysis: technique for converting between units
unit equality: 1 gal = 3.785 L
1 foot = 12 inches
See p. 38!
260 cm = ? inches
38 km/hr = ? m/s
Graphing
Wh
2-3: Matter
matter: anything that has mass and volume
States of matter:
1) solid: holds a particular shape and has a
definite volume (orderly arrangement of
molecules)
2) liquid: does NOT hold its sha
3-3: MODERN ATOMIC
THEORY
ATOMS
contain protons, neutrons, and electrons
(which can also be subdivided into quarks,
gluons, mesons, muons, etc.
It takes approximately 2000 electrons to equal the
mas
1-4: UNITS OF MEASUREMENT
Scientists use the metric system!
metric system: uses base 10
SI units: International System
fundamental units:
length- meter (m)
mass- kilogram (kg)
time- second (s)
Other U
1-5/1-6: UNCERTAINTY
OF MEASUREMENT &
WORKING WITH
NUMBERS
Uncertainty:
1) Measuring instruments are never completely free of
flaws.
2) Measuring always involves estimation.
Measure to the nearest
2-2: Temperature
Galileo: invented first thermometer
Fahrenheit: made his own scale for his
popular thermometer
Scientists now prefer the Celsius scale
more compatible with the metric system
- at sea
4-1: Radiant Energy
light: has properties of waves and properties of particles!
- light waves are electromagnetic radiation (like x-rays, gamma
rays, radio waves)
4 wave characteristics:
1) amplitude: