Unit 3 INTRO Calculating Density

Tuesday, November 8 Using scientific vocabulary, try your best to explain what is happening in this photograph.

What makes it happen? Beginning course details and/or books/materials needed for a class/project.

DENSITY Density is defined as mass per unit volume. It is a measure of how tightly packed and how heavy the molecules are in an object. Density is the amount of matter within a certain volume.

Density Formula Density is mass divided by volume. Density = mass/volume The unit for mass is grams The unit for volume is mL or cm3 The unit for density is… g/mL or g/ cm3

Units for density g/cm3 or g/ml Formula: M = mass V= volume D = density M = D x V V = M / D D = M / V

Answer the following question, using the magic triangle. What is the mass of an object if the density is 25 g/mL and the volume is 5 mL?

Answer the following using the correct units. What is the volume of an object if the density is 75 g/mL and the mass is 125 g?

Density is the Mass per unit Volume What is Density? If you take the same volume of different substances, then they will weigh different amounts. Wood Water Iron 1 cm3 1 cm3 1 cm3 IRON 0.50 g 1.00 g 8.00 g Q) Which has the greatest mass and therefore the most dense? Density is the Mass per unit Volume

Water and Density Since 1-gram of water has a volume of 1-mL then the density of water =1 gram/mL. 5o-mL of water will have a mass of 50 grams so again the density of water =1 g/mL. A kg of water will have a volume of 1000-mL so again the density of water =1 gram/mL.

Objects that Sink Objects with a density greater than 1 g/mL will sink in water.

Neutral Buoyancy Objects with a density equal to the density of water will float in mid water, at what ever level you place the object. Fish and submarines control their depth by changing their density.

DENSITY g/cm3 Aluminium 2.70 Iron 7.86 Brass 8.50 Wood 0.50 Slate 2.80 Glass 2.50 Lead 11.3 Marble 2.70 Wax 0.89

Density! In liquids… Things that are more dense sink to the bottom Things that are less dense rise to the top A schedule design for optional periods of time/objectives.

Which is more dense? Inference: Evidence:

Which is least dense? Evidence: Inference

Which LIQUID is more dense? Evidence Inference

What the heck is density? Density is the amount of matter packed into a certain space. Less dense Introductory notes. More dense

What the heck is density? Density is the mass of a substance divided by the volume of the substance. Density = mass/volume A list of procedures and steps, or a lecture slide with media.

I LOVE DENSITY!

Need to make two measurements Mass The amount of matter in a substance Kinda like how much it weighs Volume The amount of space a substance takes up Kinda like how big it is

Need to make two measurements Mass Measure with a triple beam balance Volume Measure with a centimeter ruler

But How… Mass Start with sleds at 0 100 grams? 10 grams? 1 gram? Volume Little lines are 0.1 cm Measure length Measure width Measure height Volume = l x w x h

Practice Reading

Density units Mass Measure in grams Volume Measure in centimeters 3 times cm3

Another way to measure volume If you’ve got stuff that is not a cube… Put some water in a graduated cylinder Make note of the amount of water Drop in “the thing” Note the new water level Subtract

Metrics is so cool! cm3 = ml

How to calculate Density