Chemisty Help

[virtueixi]

I got these 2 problems and I don't understand them, I keep getting the wrong answer. Plz Somebody Explain!!

The radius of a gold atom is about 1.43 angstroms. Use this measurement to calculate the volume of a gold atom in picometers cubed volume = 4/3 P r3

and

The diameter of a certain atomic nucleus is 2.30 x 10-3 pm and its mass is 3.20 x 10-23 g. What is the density of the nucleus in grams per centimeter cubed ? Assume the nucleus is a sphere with a volume equal to 4/3 P r 3

Scientific form for this one.

Thx to anyone who can help.

 

[dighn]

those are like geometry problems

the first question should be really straightforward... just plug it in. the only problem you might have is convert angstroms cubed to picometers cubed. just look up the coversion from a->pm and cube it

second, well that's really straight forward too. just calculate the volume, convert to centimeters cubed then divide mass/volume

 

[fatalbert]

the first question is simple. convert the 1.43 angstroms into picometers

1 Angstrom= 100 Picometers

then plug it into the volume formula 4/3 * pi * r^3

 

[fatalbert]

for the second, convert the picometers into centimeters, then plug into the volume formula, after dividing the diameter by 2 to find the radius. then Mass over volume = density

 

[virtueixi]

So for the 1st one it would be:

4/3 x Pi x (143)cubed =12248889.638367798021953508026519??

 

[Krakerjak]

whoooo

 

[virtueixi]

thx for the help guys. I REALLY appreciate it. The 1st answer seems 2 be incorrct though...

 

[virtueixi]

the second one is however.