Terms in this set (20)
Density depends on what 2 properties?
mass and volume
amount of matter in an object
amount of space that the object takes up in three dimensions
Formula of density
Will the densities of 2 objects with the same volume be the same?
No. It depends also on mass.
What is the difference b/w mass and weight?
Mass is the measure of the amount of matter that makes up an object. Weight is the measure of the force of gravity on a certain mass.
Does a scale measure mass or weight? Why?
Mass because scales are programmed or calibrated to actor out the effect of gravity.
How does the arrangement of atoms impact density?
If the atoms of an object are packed closely together, it will have a higher density because the volume decreases. (D= m/v). If the atoms are spread apart, the volume increases which decreases its density.
What is the water displacement method?
It is a method to measure the VOLUME of an object depending on the amount of water that it displaced.
How do the water displacement methods work?
1. In a graduated cylinder of water, the volume of an object will be the initial water level (before putting the object into the cylinder) subtracted from the final water level (after the object is inside the cylinder)
2. Fill a cup as much as possible with water. Place the object into the water and let it sink or push in below the surface if it floats. Measure the volume of the water that was displaced by the object.
Fill in the blank: The density of an object is the _______ no matter what the size of the sample.
What 2 factors determine whether an objects floats or sinks?
The density of the object and the density of the liquid it is suspended in.
Can a liquid float or sink in another liquid?
Give an example of two liquids that sink or float when combined.
Oil is less dense than water so it floats above water. Alcohol is less dense that oil so it floats above the oil.
What are 2 ways to make an object that normally sinks, float?
1. Increase the density of water 2. Increase the volume of the object.
What do some objects that sink, float in the Dead Sea?
The Dead Sea is very salty. The salt water is more dense than regular water. As such, some objects that normally sink can float in the more dense water at the Dead Sea.
If you are told that an equal volume of water has more mass than an equal volume of wax, what does that tell you about their densities?
D=m/v. So if the volumes are equal and the water has a greater mass, then the water is more dense than wax.
Explain why heavy boats float.
D= m/v. If the mass is constant, but the volume is enlarged, this decreases the density.
What happens to the density of water when it is heated? Why?
Density decreases. When water is heated, the molecules move faster and gets slightly further apart. The water still has the same mass but it takes up a larger volume. The larger volume leads to a decrease in density.
Why does ice float?
Water is special. When water freezes the molecules get further apart as they orient themselves into a crystal structure. This increase in volume decreases density. Thus, the ice floats above the denser water.