The chemical formula for magnesium sulfate is MgSO4, so it shows that there are four atoms of oxygen but not sulfur. There is only one atom of sulfur in the formula
Iron rusts when exposed to air → chemical property
Answer:

Explanation:
Given,
The density of Helium is 
We need to find the density in Dg/μm
We know that,
1 g = 10 dg
1 cm³ = 10¹² μm³
So,

So, the density of Helium is equal to
.
Answer:
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Explanation: