Volume, Mass, and Density
To find density, first you need to find the mass and volume of an item.Volume
Regularly shaped solids: A regularly shaped solid is something like a cube or a rectangular prism. To find the volume of these items you should first measure the width, the height and the length of the item using the same unit of measurement (usually centimeters). After finding the measurements, multiply them together. Now, to record your volume, take the unit of measurement and write a cubed sign afterward. An example of this is if an item's measurements were 5 cm X 7 cm X 2 cm your volume would be 70 cm3.
Irregularly shaped solids: To find the volume of an irregular solid, you would use the water displacement method. The water displacement method can be used in two different ways.
Method 1: If you have an item which will fit inside your graduated cylinder, you should fill the graduated cylinder to a set point (record this level), then gently drop the item in. After finding the new level of the water, subtract the original amount of water in the graduated cylinder from the new level of water and the difference is the volume of your irregular solid.
Method 2: To find the volume of a larger irregularly shaped solid which will not fit in a graduated cylinder, you should use the following method.
Note: This method leaves room for error. Errors may occur if the container filled with water is not filled to the exact highest point.
Step 1: Fill a container completely full with water. Place an overflow container beneath it.
Step 2: Place the object carefully in the water filled container (if not extremely careful while placing an item in the water, splashing may occur and taint your results).
Step 3: Measure the amount of water that spills to the overflow container to find the volume.
Liquids: to find the volume of a liquid, simply pour your liquid into a graduated cylinder and read the results. Be sure to read from the lowest point of the meniscus (unless you are finding the volume of mercury).
Mass
Mass is the amount of matter in an object and it is fairly simple to find.
First, you turn on your balance and zero it. Make sure that your unit of measurement is grams. Next, you place the item you want to mass onto the surface. Finally, you record the number and your done.
First, you turn on your balance and zero it. Make sure that your unit of measurement is grams. Next, you place the item you want to mass onto the surface. Finally, you record the number and your done.
To find the mass of either a liquid or a solid that may be flaky, or falling apart, you need to find a container to place it in. Before placing the object to be massed in the container, put your container on the balance; zero the scale, and proceed as usual.
Density
The equation for finding density is D=M/V in which D is the density, M is the mass of an item, and V is the volume of the item. So basically, to find the density of an item, take the mass and divide it by the volume. When solving for density, the mass should be in terms of grams and the volume should be in terms of either mL if it is a liquid, or cm3 if a solid. For example, if an object's volume is 70 cm3 and the mass is 140 grams, you would divide 140 grams by 70 cm3 to get the density of 2 grams/ 1 cm3.
When writing the density of an object, write it with the number you got correctly labeled over 1 cm3 (or mL).
Density is the amount of matter an object has in a certain amount of space. This means that if item A has a density of 2 grams/ 1 cm3 and if item B has a density of 1 gram/ 1mL then for equivalent amounts of items A and B, item A will have twice the amount of matter than item B has and therefore, twice the mass.
Density has a huge affect on our natural world. Density determines if an item will sink or float in different liquids. If an item (solid or liquid) has a higher density than the liquid it is put into, it will sink to the bottom. But if it is less dense, then it will float.
In this picture the yellow liquid has the highest density, the red liquid has the second highest density, followed by the clear liquid. The black liquid has the lowest density. This is evident due to the clear separation of the liquids in that order from bottom to top.
