It is b I hope this helps
Explanation:
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One mole of Na2SO4 is 6.022 * 10^(23) molecules. We can divide this into the quantity in the question to find a value of 1.5/6.022 = 0.2491 moles. Rounded to two significant figures and put in scientific notation, we can rewrite this quantity as 2.5 * 10^(-1) moles
When two atoms of Florine combines, they share an electron pair to complete it's octet. This result is formation of single bond between two fluorine atoms. This process is exothermic in nature, and hence, heat is liberated during the process of bond formation. <span />
