The formula for magnesium chloride is mgcl2 how many magnesium atoms are there in one molecule

18. use the activity series to predict whether the following synthesis reaction will occur. write the chemical equations for the reaction if it's predicted to occur. (s) + o2(g) -> *note: it is possible.*

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?

Find the number of grams of hcl needed to react completely with .50 moles of magnesium.