2. Fact: an observation that has been repeatedly
confirmed and is accepted as true.
Theory – explanation for hypothesis and
observations that have been supported by
testing, it explains and predicts
Law – summary of many experimental results
and observations, tells you how things work
Vocabulary
3. Scientific Models
A model is a substitute or stand-in for what
you are actually studying or trying to
predict. They are convenient. Models are
similar to what they represent even if they
are not exact:
• can be larger or smaller
• can be different colors
• may not act the
same
• they do have limitations!
.
4. Types of Models
Physical Models- look like the
item they are modeling.
Ex. A globe is a physical model
of the earth.
Mathematical Models– made up of
mathematical equations and data.
Ex. Newton’s Law in Physics.
5. Types of Models
Conceptual Models –
system of ideas,
groupings, or
classification.
Ex. Kingdoms and
Domains.
6. Measurement
International System of Units (SI System)
• Metric System
• Used all over the World
• Improves communication between scientists
KHD_M_DCM model
Mnemonic!
King Henry Dances Merrily Down Central Main
Lazily
Gracefully
Base Units Change
M = meters
L = liters
G = grams
7. K H D_M_D C M model
Mnemonic!
King Henry Dances Merrily Down Central Main
Lazily
Gracefully
The others are prefixes
K = Kilo = x1000
H = Hecto = x100
D = Deka = x10
d = deci = x .10
c = centi = x .100
m = milli = x .1000
Base Units Change
M = meters
L = liters
G = grams
8. Measurement
Length
SI Unit - meter
Area
How much surface an object has
Area = Length x Width
= square units = cm2
, m2
, km2
L
W
9. Measurement
Volume
Amount of space something occupies or
amount of space something takes up
Volume = Length x Width x Height
= cubic units = cm3
, m3
, km3
(volume of a rectangular prism)
L
W
H
Volume of irregular shaped objects?
10. Measurement
Volume of irregular shaped objects
Amount of space something occupies or
amount of space something takes up
Volume = Amount of water the object displaces
= cubic units = mL3
, L3
11. Measurement
Mass
Amount of matter in an object.
Usually measured in kilograms (large items)
or grams (small items)
Which has more mass, a kilogram
of feathers or a kilogram of bricks?
12. Measurement
Weight
The pull of gravity on an object or how
heavy something is.
Usually measured in kilograms (large items)
or grams (small items)
Where do you weigh more, Earth or the moon?
13. Measurement
Density
A physical property that describes the mass
per unit volume of a substance.
Mnemonic –
Density is a “broken heart”.
D = ---------- or Density = --------------D = ---------- or Density = --------------Mass
Volume
14. Measurement
Temperature
Measure of how hot or cold an object is
Expressed as degrees Fahrenheit,
degrees Celsius, or Kelvin (SI)
• Water boils at 212° F and 100° C
• Water freezes at 32° F and 0° C
• Body temperature is about 98.6° F
