New Month, New Mentality.

What? MCJC writing their blog the night of Chemistry Class?! No Late Cramming?! I'm not going to lie, I think I have a fever this is so weird. Anyway, today was the first day of November, and we were brutally welcomed to the 11th month of the year to a thrilling quiz that was so much fun I almost felt like writing it again! Okay, it is 6 months until April fools, why not throw in a joke? Moving on, after our spantastic quiz on Significant Figures, we took some beautiful written notes on Density. Now even though I am one of the brightest scientists you will ever meet, I will tell you about these notes we were given.

The Density of a substance is also know as its mass over volume. To calculate an object's density, you quite simply divide mass over volume. D = m/v

Now for most non-scientists, this is where it gets tricky. Well, not really. It just sounds cooler when I say that and when I hear/read that, more often then not I actually decide to listen rather than just pretend to.

For a solid substance, the most commonly used measurement is g/cm3.
For a liquid substance, it is usually g//mL. *** 1 cm cubed of Water = 1 mL

So we know how to calculate the Density, and the units, but what next?

Well, if the density is greater than the liquid's, than the object will sink.
If the density is less than the liquid's, the object will float.

Object > Liquid = Sink
Object < Liquid = Float.

You want an example? I don't. But here is one.
Eg. Calculate the density of an Iron Bar if the bar weighs 1200 grams, with a volume of 1.25L.

D= m/v D = 1200g/1.25L
D = 960 g.
** REMEMBER the units, grams and Litres.

That is all!!! YAY!!!


Here are a couple of videos that we found helpful....

http://www.youtube.com/watch?v=rxb_6UANXqU

http://www.youtube.com/watch?v=Q4EBOE4pJyw&feature=related



ENJOY!