12 x 10^23 atoms, i hope this helps
Density (p) is defined as the mass (m) per unit volume (v) or:
p = m/v
Using this relationship, the volume is:
v = m/p
Using the given values of mass of 80 grams and density of 8 g/cm3, the sample volume is:
v = 80 grams/8 grams/cm3
v = 10 cm3
The final answer is 10 cm3.
Im not sure if this will help but... your subscripts in a balanced equation are used to calculate the molar mass of the compound. And your coefficients are used to get the ratios. so for example we have this balanced equation
Be3N2 + 6H2O= 3Be(OH)2 + 2NH3 and you have to find the molar mass of 6h2o, you need to multiply the subscript by the atomic mass and then add them together to get the overall molar mass. * 2(1.01) + 16.00= 18.02 g/mol
and if a question wants to know the limiting or excess regent you would use the coefficients to find out the ratio between the compounds.
Number of moles = mass/ molar mass
= 45.6g / 88.90g/mol
= 0.512 moles
Radium is a radioactive element, according to the periodic table of elements, Radium IS more radioactive than uranium.
