Answer:
More than 40 percent measured above 5 ppb of lead, which the researchers considered an indication of a “very serious” problem.
Answer:-
2747.7 Cal mol -1
Explanation:-
Molar heat of Fusion is defined as the amount of heat necessary to melt (or freeze) 1 mole of a substance at its melting point.
Atomic mass of Iron = 55.845 g mol-1
Mass of Iron = 200 g
Number of moles of Iron = 200 g / (55.845 g mol-)
= 3.581 moles
Heat released = 9840 Cal
Molar heat of Fusion = Heat released / Number of moles
= 9840 Cal / 3.581 moles
= 2747.7 Cal mol -1
The answer you are looking for is "bromine". Hope this helps!
