Density

DENSITY Density is used to describe how concentrated, or how packed, the atoms and molecules in an object are. Less Dense More Dense

Which of these objects would float on water? Water has a density of 1 Therefore, an object with a density more than one will sink in water. An object with a density less than one will float in water. Which of these objects would float on water? Wood 0.6 Quartz 2.5 Ice .9 Styrofoam 0.01 Aluminum 2.70 Gold 19.3 FLOAT SINK FLOAT FLOAT SINK SINK

HOW DO YOU DETERMINE THE DENSITIES OF OBJECTS In order to find the density of an object you must know the mass and the volume of that object Density = mass ÷volume (d=m/v)

MASS Mass is the amount of matter in an object You can find the mass of an object by using different types of scales. Weight is different from mass. Weight is the force of gravity on an object.

Volume = length x width x height. The volume of regularly shaped objects can be found by measuring their width, length, and height. You use the following formula: Volume = length x width x height.

VOLUME To find the volume of an irregularly shaped object you use the water displacement method. This method involves dropping the object into a measured amount of water and seeing how much the water level rises.

In order to find the displacement of water you must know how to read the meniscus correctly! Correct Reading: 73 mL

What is being measured in this picture? ____________ Volume

25 mL

Same volume Different Mass Different volume Same Mass

M D V Density = mass divided by volume x The Density Triangle: a good way to find any of the three: mass, volume or density Density = mass divided by volume M=mass Units: g, mg, kg M . . V=volume Units: mL, L, cm³ D V x D=density Units: g/mL, g/L, g/cm³

IMPORTANT EARTH SCIENCE FACTS 1. __________is how close or compact the molecules are. 2. The ________ substance has the same density, no matter what the size. 3. As temperature increases, molecules spread out (Volume Increases) and density __________________. 4. Warm (air, water, magma) rises because it is _____________ Cold (air, water) sinks because it is more dense. 5. Density = _________________________ Density same decreases less dense Mass/Volume

6. The units used to measure density are: ______________ shaped objects---gms/cm³ ______________ shaped objects---g/ml Volume for irregular objects is found by ______________________ The density of water is________. 9. For objects with densities less than 1, the lower the density is, the ___________ it floats in water. Regular Irregular water displacement 1g/ml higher

“Crowdedness” Do these have the same density? M = 6g V = 1cm3 D = M = 4g V = 1cm3 D = M = 16g V = 4cm3 D = M = 6g V = 4cm3 D =

Which of these has the same density? M = 6g V = 1cm3 D = M = 4g V = 1cm3 D = M = 16g V = 4cm3 D = M = 6g V = 4cm3 D =

Which of these has the highest density? M = 6g V = 1cm3 D = M = 4g V = 1cm3 D = M = 16g V = 4cm3 D = M = 6g V = 4cm3 D =

Which of these has the lowest density? M = 6g V = 1cm3 D = M = 4g V = 1cm3 D = M = 16g V = 4cm3 D = M = 6g V = 4cm3 D =

What would be the density of another sample of the same material that is 8cm3 ? M = 6g V = 4cm3 D =