`In this lesson we discussed how to abbreviate electron configurations using what is called noble gas configuration. So if you were writing such a configuration for phosphorus, which noble gas would you use?

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?

How many moles is 14.5 cm^3 of platinum? the density of platinum is 21.45 g/cm^3.

What is the atomic number of an atom that has 6 protons