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. Which has the greatest density? Why? Density Notes
Jan 21, 2016
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. Which has the greatest density? Why?
Density Notes
Which one is more dense?
Demonstration: People in a square
How about this: Which square is more dense?
Which one is more dense?
Now which one is more dense?
Two related terms of Density• 1- Mass- the amount of matter in an object;
it is how much stuff an object has
• Unit used for mass is grams (g) and kilograms (kg)
• How measured: scale
Which has more mass? Why?
2 term related to Density
• Volume- the amount of 3-dimensional shape an object occupies
• Can be measured by:
Volume = L * W * H (box or cube)
Graduated Cylinder (for a liquid) (beaker)
Displacement (irregularly shaped object)
Units for volume: cm3, in3, Liters (L), mL
Volume
1) Which has the greatest volume? Figure it out.
2) Which has the greatest volume?
Calculating Density
The formula for density is:
Density = Mass
Volume
Units: g/mL, g/cm3, kg/L
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
1) Find the mass of the object
2) Find the volume of the object
3) Divide : Density = Mass - Volume
To find density:
Set up your density problems like this:
Givens: Unknown:
Formula: D = M / V Solve
Ex. If the mass of an object is 35 grams and it takes up 7 cm3 of space, calculate the density.
• Calculate the volume of a liquid with a mass of 10 g and whose density is 2 g/mL. - givens:– unknown:– formula for unknown: – plug in values and solve.
To find the density1- Find the mass of the
object- use a scale
2- Find the volume of the object-
3- Divide Density = Mass
Volume
Density Units
• Density- the amount of mass in a given volume.
• Density = mass / volume
• Units- kg/L or kg/m3
g/mL or g/cm3
• The density of gold is approximately 19 g/cm3
1) How much would 2 cm3 of gold weigh?
2) What is the mass of 1 cm3 of gold?
• A liquid has a density of 2 g/mL. What exactly does this mean?
• A liquid has a density of 1.5 g/mL.
1)What is the mass of 1 mL of this liquid?
2) What is the mass of 2 mL of this liquid?
3) What is the mass of ½ a mL of this liquid?
Proof that water and ice have different densities
1) Find the mass of the object
2) Find the volume of the object
3) Divide : Density = Mass - Volume
To find density:
Ex. If the mass of an object is 35 grams and it takes up 7 cm3 of space, calculate the density.