Answer:
Explanation:
Calcium is all around us. The average human contains approximately 1kg of calcium, of which 99% is stored in our bones. It is the 5th most abundant element in the earth's crust, occurring widely as calcium carbonate which is more commonly known as limestone. It is also the fifth most abundant dissolved ion in seawater.
Atoms are the basic units of matter and the defining structure of elements. We count the number of atoms by the total number of elements present in the compound. In this case, we have 1 atom of Si and 2 atoms of oxygen which would have 3 total number of atoms.
You must remember that oxidation number of hydrogen in acids is always +1, oxidation number of oxygen in oxides & acids is always -2... metals has always oxidation number on plus!
group NO3 comes from HNO3...and oxidation number of whole acid group is always on minus and equal to the amount of hydrogen atoms in this acid... so oxidation number of NO3 = -1
we have 2 NO3 groups so 2*(-1) = -2 and that is the reason why oxidation number of Fe in this formula must be +2... because sum of all elements always gives 0!
Now we could count of oxidation number for nitrogen... we write HNO3 and start counting from right to left:
3*(-2) from oxygens + 1 from hydrogen = -5
so nitrogen must have +5 oxidation number... because sum all in formula must be 0.
255 Newtons hope this helps
there are 6 moles of oxygen in Zn(No3)2
