Notes: Measuring Matter

MASS

������

MATTER: (stuff) consists of a combination of particles called atoms. Almost everything is matter!

MASS: a measure of the amount of matter

(stuff) an object is made of. WEIGHT: a measure of the PULL OF

GRAVITY on a MASS.

Mass vs. Weight Measured using a balance. Measured using a scale.

Units = grams (g) suffix. Units = Newtons (N), pounds, ounces.

Amount of matter (stuff). Pull of gravity on a mass. Weight is a FORCE!

Not affected by gravity. Changes when gravity changes.

Can only change by adding Changes when mass changes removing matter. and/or gravity changes.

Same on the Moon, Jupiter 4.5x greater on Jupiter and every place else. 6x less on the Moon.

Massing Practice

Object Description mg g kg Comp Book

Steel Bolt

Oak Block

Cork

Penny

Graduated Cylinder

50 ml Water

Index Card

Brass Pipe

Steel Nut

I can use a balance to find the mass of an unknown object

Measuring Mass

Top Image: http://www.southwestscales.com/Ohaus_Triple_Beam_750-SO.jpg���Bottom Image: http://www.regentsprep.org/Regents/biology/units/laboratory/graphics/triplebeambalance.jpg

We will be using triple-beam balances to find the mass of various objects.

The objects are placed on the scale and then you move the weights on the beams until you get the lines on the right-side of the scale to match up.

Once you have balanced the scale, you add up the amounts on each beam to find the total mass.

What would be the mass of the object measured in the picture?

_______ + ______ + _______ = ________ g

Measuring Mass – Triple-Beam Balance

Click here to try an online activity.

1st – Place the film canister on the scale.

2nd – Slide the large weight to the right until the arm drops below the line. Move the rider back one groove. Make sure it “locks” into place.

3rd – Repeat this process with the top weight. When the arm moves below the line, back it up one groove.

4th – Slide the small weight on the front beam until the lines match up.

5th – Add the amounts on each beam to find the total mass to the nearest tenth of a gram.

•  VOLUME: (space) - the amount of space an object takes up (occupies) .

§ Units: anything with the suffix “liter” or any linear measurement cubed. There are also English units such as cups, pints, quarts, gallons etc.

§ 1 milliliter = 1 centimeter cubed (cm3, cc)

§ 1 cm3 H2O = 1 ml H2O = 1 gram H2O

MEASURING VOLUME:

§ RULER – used to measure regular shaped objects (i.e. cubes, cylinders, prisms etc.)

§ GRADUATED CYLINDER – used to measure liquids.

***Read the volume measure at the bottom of the meniscus.

§  DISPLACEMENT METHOD - Use for irregular shaped objects. *** Object must be fully submerged!

Volume Practice

Regular Shaped Objects (LxWxH) Object Description cm3

Ant Cube L= W= H= Small Block L= W= H= Gray block L= W= H= Wilson Art

Tile L= W= H=

I can find the volume or regular and irregular shaped objects.

Volume Practice

Irregular Shaped Objects (Displacement)

Object Description ml

I can find the volume or regular and irregular shaped objects.

DENSITY: The measure of the amount of matter (stuff) in a measured amount of volume (space). § Units: any UNIT OF mass “per” unit OF

volume. § Examples: g/ml kg/m3 kg/L

g/cm3 g/cc g/L § Calculating density:

§ Find the mass and volume of the object. § Calculate:

D = m V

Which is more dense? Explain your answer.

Densities of common substances: Water @ room temp = 1.00 g/ml

Ice @ 0 degrees Celsius = 0.917 g/ cm3 Gold = 19.3 g/ cm3 Iron = 7.87 g/cm3 Aluminum = 2.7 g/ cm3 Wood = 0.11 – 1.33 g/cm3

Helium = 0.0001786 g/ cm3 Air (Dry @ 1 atmosphere) = 0.00119 g/ cm3

PRACTICE PROBLEMS: ���Solve using the “4 Step Method”

1. List the knowns and unknowns. 4 STEP METHOD:

2. List the equation/s that will be used to solve the problem. 3. “Plug and Chug” – solve the problem.

4. The ANSWER – with correct units

Problem #1: Find the density of a block that has a volume

of 25 cc and a mass of 200 grams.

Problem #2: A block of material has a length and width of

2 cm and a height of 5 cm. The block has a mass of 5 grams. What is the density of the block?

Lab - Finding Density Item Description Mass Volume Density

Glue Stick Clothespin Wilsonart Oak Pine (red) Pine (blue) Copper Penny Steel Bolt Cork Brass Pipe Steel Tube Marble

Lab - Finding Density Item Description Mass Volume Density

Candle Hot Glue Wilsonart Oak Pine (red) Pine (blue) PVC Copper Steel Bolt Cork Brass Steel Tube