The symbol is ba. The number of neutrons equal the number of protons
Answer: The moles of melatonin are 0.000043
Explanation:
According to avogadro's law, 1 mole of every substance weighs equal to its molecular mass and contains avogadro's number 
of particles.
To calculate the moles, we use the equation:
Given mass of melatonin = 0.01 g
Molar mass of melatonin 
= 232.28 g/mol
Thus the moles of melatonin in 0.01 g are 0.000043
Answer:
Percentage recovery of acetylferrocene = 81.6%
Explanation:
Mass of the sample mixture = 22.092 g
Ratio of mixture of acetylferrocene and ferrocene = 1 : 1
This means that the sample conatains equal amounts of acetylferrocene and ferrocene.
Therefore the mass of each sample in the mixture = 22.092 g / 2 = 11.046 g
Mass of acetylferrocene recovered = 9.017 g
Percentage recovery of acetylferrocene = (mass of recovered/ mass in sample) * 100%
Percentage recovery of acetylferrocene = (9.017 g / 11.046 g) *100%
Percentage recovery of acetylferrocene = 81.6%
