Write the empirical formula of at least four binary ionic compounds that could be formed from the following ions:
Mg+2, Cr+4, I−, S−2

If a plot weight (in g) vs. volume (in ml) for a metal gave the equation y= 13.41x and r^2=0.9981 what is the density of the metal?

This is a characteristic of the elements in the periodic table that shows a pattern. it may increase or decrease across or down the table.

How many moles of lead are in 1.50 x 10^12 atoms of lead? could you explain the answer as well and not just give it to me i am refreshing for finals and i need to know how to do it