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: B
Explanation: to have a control, and many samples to investigate and cover the differences and anseretics.
anything that turns red litmus paper to blue it is an acid and vice versa is true
Answer:
c ) 29.4 psi
Explanation:
If the density of earth was twice than its actual density which is 5.51 g/mL, then at sea level the atmospheric pressure of earth in British units would be equal to 29.4 psi because increase of gravity, increase occurs in the atmospheric pressure. If we double the gravity of earth by double of the earth density, so the weight of that same mass of air will be double which leads to the doubling of the atmospheric pressure at the sea level.
In comparing two isotopes of the same element, the atomic number, stays the same.
Allow me to explain: The protons in an isotope ALWAYS stays the same, but the neutrons change. But, what's the atomic number made up of?
Protons, which means it won't change.
However, the atomic mass is made up of neutrons + protons, so only the atomic mass would change - not the atomic number.
