They have the same density because a material, no matter how much of it there is, will always be a certain density. A 40g ball of iron has the same density as a 1g ball of iron.
First of all, you should know the valence electron of atom.
Then add charge, In case of -ve ion & subtract, in case of +ve ion.
You'll need Avogadro's number for this. NH3 has 1 Nitrogen and 2 Hydrogen. You'll multiply the molar mass of each times Avogadro's number. So:
molar mass N x 6.022x10^23 x 1 Nitrogen= total A
Molar mass H x 6.022x10^23 x 2 Hydrogen= total B
Add total A+B = your answer
I don't have a calculator or periodic table but if you plug in the numbers you'll get your answer. Hope it helps.
There is a typo in the question. hopefully, i assumed the correct number.
when volume and temperature are given, that means you need Charles' law. remember that with any gas formula, the temperature has to be in Kelvin which can be determined by simply adding 273 to Celsius.
Charles' law---> V1/T1 = V2/T2
V1= 2.8 m3
T1= 20 C = 293 K
V2= 0.2 m3
T2= ????
let's plug in the values
2.8/ 293 = 0.2/ T2
T2= 20.9 Kelvin
to change the answer to Celsius, just subtract 273 to the temperature
20.9 - 273= -252 Celsius
