PLEASE HELP WILL MARK 1. If a cube has 2cm sides and a mass of 10 g, what would it's density be?
A. 0.8 g/cm3
B. 1.25 kg
C. 1.25g/cm3
D. None of the above

2.If a cube has sides of 1.5 cm, and a mass of 15 g, would it float or sink in water?
A. float
B. Sink

3. A material with a melting point of 25C would be a solid at 15C?
A. True
B. False

4. A material with a Chemical Symbol of CO is an element.
A. True
B. False

Does anyone know a lot about how to: - calculate mass of magnesium metal - calculate the actual yield of magnesium oxide - calculate the theoretical yield of mgo - calculate the percent yield of mgo - determine the percent yield of mgo - determine the average percent yield of mgo i had to do an online lab and its asking these questions but i have no idea where to start or how to be able to find these things. i can post the chart of the data from the lab or if you can tell me exactly how i can find each.

Draw the skeletal structures of two different molecules that are each made of 5 carbon atoms and 12 hydrogen atoms.

Tin has ten stable isotopes. the heaviest, 124sn, makes up 5.80% of naturally occuring tin atoms. how many atoms of 124sn are present in 82.0 g of naturally occurring tin? what is the total mass of the 124sn atoms in this sample?