How many moles are in 0.0073 kg of tantalum?

Tantalum is the 73rd element in the periodic table with an atomic mass equal to 180.95 g/mol. To determine the number of moles present in the given mass of tantalum above, we simply divide the mass by the atomic mass. 
                   number of moles = (0.0073 kg)(1000 g/ 1kg) ÷ (180.95 g/mol)
                   number of moles = 0.0403 moles
Therefore, there is approximately 0.0403 moles of tantalum in 0.0073 kg. 

With 100g of KClO3, we get is 0.816mol of it (divide mass given by formula mass of 122.55 g/mol). therefore, there will be 47.9167g of KCl produced from KClO3 when it is decomposed.

Explanation:

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