Matter, Energy and Measurement

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Chemistry B11
Chapter 1 Matter, Energy and Measurement
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Chemistry and our life
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Chemistry Matter
Matter has mass and takes space.
Chemistry science that deals with matters and
their changes.
Central Science
All sciences are connected to chemistry.
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Changes
Chemical change (chemical reaction)
substance(s) are used up (disappear) ? others
form burning or
cooking the egg
Physical change identities of the substances do
not change. (change of state) evaporation of
water or melting
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Scientific method
fact is a statement based on direct experience.
hypothesis is statement that is proposed without
actual proof.
theory is the same as a hypothesis except that
we have a stronger belief in it because of more
evidence supports it.
serendipity observation by chance
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Exponential notation
based on power of 10
10000 1104 0.0001 110-4
4500000 4.5106
0.000078 7.810-5
94800 9.48104
0.0121 1.2110-2
Positive power greater than 1 Negative power
Less than 1
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Exponential notation
Power, Exponent
9.23 ?1025
Base
Coefficient
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Exponential notation
(3.62 106)(7.43 103) 26.90 109 2.69 1010
3.62 107
2.68 102
1.35 105
Decreasing the power one point
Moving the decimal point to right
Increasing the power one point
Moving the decimal point to left
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Measurements
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Measurements
Measurement consists of two parts Number -
Unit
2 pounds
Unit
Number
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Measurement and Units
Metric system or SI (International System of
Units)
meter, liter, gram
English system (use in the United States)
miles, gallons, pounds
Advantages of SI we have base unit for each kind
of measurement other units are related to the
base unit by power of 10.
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base unit of length meter (m)
1 kilometer (km) 1000 meter (m) 1 centimeter
(cm) 0.01 meter (m) 1 nanometer (nm) 110-9
meter (m)
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Tools (equipment) of measurement
Length Meterstick or Ruler Volume Graduated
cylinder, Pipette
Mass Balance
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Temperature
Fahrenheit (F)
english system
Celsius or centigrade (C)
metric system or SI
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Temperature
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Conversion of Units
Factor-Label method
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States of Matter
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Density and Specific gravity
density mass per unit volume
d density (g/mL or g/L) m mass V volume
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Energy
Kinetic energy (KE) energy of motion KE ½
mV2 V velocity
Potential energy stored energy
Law of conservation of energy
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Heat and Temperature
units of heat calorie (cal) or joule (J)
1 cal 4.184 J