Density Of Materials Flashcards
What is Density a measure of?
Density is a measure of the compactness of a substance. I’m relates the mass of a substance and how much space it takes up (i.e it’s a substance’s mass per unit volume).
What does the density of an object depend on?
It depends on what it’s made of and how it’s particles are arranged.
A dense material-
Has its particles packed tightly together.
A less dense material-
The particles in a less dense material are more spread out
What would happen if you compressed the material?
It’s particles would move closer together, and it would become more dense. (You wouldn’t be changing it’s mass, but you would be decreasing its volume.)
Difference between solid, liquid and gas?
Only the arrangement and energy of the particles are different.
Solids-
Strong forces of attraction hold the particles close together in a fixed regular arrangement. The particles don’t have much energy so they can only vibrate about their fixed positions. The density is generally highest in the state as the particles are closest together.
Liquid-
There are weaker forces of attraction between the particles. The particles are close together but can move past each other and form irregular arrangements. They have more energy than the particles in a solid they move in random directions at low speeds. Liquids are generally less dense than solids.
Gas-
That almost no force of attraction between the particles. The particles have more energy than liquids and solids they are free to move and travel in random directions at high speeds gases are generally less dense than liquids they have low densities.
How to measure density of a solid object
1) Use a balance to measure its mass.
2) if it’s a regular solid start by measuring its length width and height with an appropriate piece of equipment then calculate volume using the relevant formula for that shape.
3) For On a regular solid you can find its volume by submerging it in the Eureka can filled with water. the water is displaced by the object will be transferred to the measuring cylinder.
4) Record the volume of water in the measuring cylinder. This is the volume of the object.
5) Plug the objects mass and volume into the formula above to find its density (density (kg/m3) = mass / volume)
To find the density of a liquid
1) Place a measuring cylinder in a balance and zero the balance.
2) Pour 10ml of the liquid into the measuring cylinder and record the liquids mass.
3) Pour another 10ml into the measuring cylinder, repeating the process until the cylinder is full and recording the total volume and mass each time.
4) For each measurement, use the formula to find the density (remember that 1ml = 1cm)
5) Finally, take an average of your calculated densities. This will give you a value for the density of the liquid.
Volume of a cube-
L x W x H
What measures volume
The eureka (density = mass / volume
Density can also be written as
p (Greek numeral for “rho”)
