1. Mythbusters Mentos Fountain
Is the Mentos Fountain a physical reaction or a chemical reaction?
On your worksheet, complete a “Claim-Evidence-Reasoning” response to this question.
Claim: make a simple declarative statement
Evidence: present the data and/or observations that you will use to support your claim
Reasoning: explain how and/or why your evidence supports your claim (refer to definitions, concepts, equations, etc. as appropriate)

2. Measurement in Science
Measurements in science use the SI System
To study motion and force, we need to measure:
Mass – how much “stuff” there is
Length – distances, areas, and volumes of space
Time – how quickly or slowly something happens
The fundamental units for these measurements:
Mass – the gram (unit symbol = g)
Length – the meter (unit symbol = m)
Time – the second (unit symbol = s)

3. Avoiding Writer’s Cramp
Sometimes our numbers get really big (think the size of the universe) or really small (think the size of electrons or other subatomic particles)
We can use exponents of 10 to avoid writing lots of zeroes
For example, 3 x 106 instead of 3,000,000
Or 5.6 x 10-9 instead of
And we can add prefixes to the basic SI units to take the place of the exponents!!

4. SI Prefixes For larger things For smaller things
Kilo- = kg = 1,000 g (one thousand)
Mega- = Mm = 1,000,000 m (one million)
Giga- = Gs = 1,000,000,000 s (one billion)
For smaller things
Centi- = cm = 1/100 m (1 one-hundredth)
Milli- = mL = 1/1000 L (1 one-thousandth)
Micro- = ug = 1/1,000,000 g (1 one-millionth)
Nano- = ns = 1/1,000,000,000 s (1 one-billionth)

5. Fluid Volumes – another option
Volume is a length times a length times a length
So, we could have volumes of m3, or km3, or mm3, or cm3 (sometimes written “cc”), etc.
It happens that for fluids (liquids and gases), 1000 cc is a very convenient volume to use
This volume is defined as 1 liter (unit symbol = L)
Thus, 1 L = 1000 cc = 1000 cm3 = 1000 ml
If the sides of a cube had a length of 10 cm, the volume of the cube would be 1 L
Liters vs cubic meters is a matter of convenience

6. Measuring Mass
On Earth, we can measure mass using a “spring scale” or a “balance”
A spring scale balances the force of gravity on the object with the force of a stretched spring
A balance balances the force of gravity on the object with the force of gravity on other masses

7. Spring Scale or Balance?
If you were going to the moon and wanted to measure the mass of a moonrock while you were there, which device should you take along with you from Earth – a spring scale or a balance?
On your worksheet, complete a “Claim-Evidence-Reasoning” response to this question.
Claim: make a simple declarative statement
Evidence: present the data and/or observations that you will use to support your claim
Reasoning: explain how and/or why your evidence supports your claim (refer to definitions, concepts, equations, etc. as appropriate)