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Offline mjgreeley

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2 Questions, Need to know where to start
« on: March 08, 2008, 05:42:00 PM »
The set below featuring one alkali, one alkaline earth, one halogen, one lanthanide and one actinide element is:
a. cesium, barium, bromine, erbium, samarium
b. francium, beryllium, iodine, terbium, berkelium
c. lithium, manganese, fluorine, lanthanum, vanadium
d. potassium, radium, iodine, lutetium, platinum
e. rubidium, strontium, chlorine, thorium, plutonium


Given this data from lab, for mass and then the volume of water displaced in a graduated
cylinder by introduction of a metal sample to the cylinder.
Mass of weighing cup = 0.452 g.
Mass of weighing cup + metal sample = 72.943 g.
Volume of water in cylinder = 15.2 cm3.
When the metal sample was carefully lowered into the graduated cylinder, the water above the submerged metal sample rose to the 19.0 cm3 mark. What is the density of the metal?
a. 2.2 g cm-3
b. 3.8 g cm-3
c. 4.8 g cm-3
d. 19 g cm-3
e. 19.2 g cm-3

I am totally lost with all of this. The first question I have no idea what they are even asking and how to go about finding out that answer. Second question, I need help trying to figure out where to start. I am completely lost when it comes to math. Thank you so much!

Offline Borek

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Re: 2 Questions, Need to know where to start
« Reply #1 on: March 08, 2008, 05:52:44 PM »
What are alkali metals? List them (they must be in your book, if not, try Google or wikipedia).
What are alkaline earth metals? List them.
Halogens? Lantanides? Actinides?

Once you will have them listed it should be easy.

Second question - split it into smaller problems.
What is sample mass?
What is sample volume?
What is density definition?

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