A chermist weighs out 400.0 g of Ca How many moles of Ca is this?

Explanation:

To find out the number of moles we use the formula

where

n is the number of moles

M is the molar mass

m is the mass of the substance

From the question

m = 400 g

M of Ca = 40 g/mol

We have

We have the final answer as

Hope this helps you

the number of valence electrons for each molecule or ion is shown beneath the structure. remember hydrogen will not have more than two electrons. this hydrogen is part of a covalent bond (sharing two electrons). a double bond here would cause hydrogen to share four electrons with phosphorus.