A national day is a day on which celebrations mark the nationhood of a nation or state. It may be the date of independence, of becoming a republic, or a significant date for a patron saint or a ruler (such as a birthday, accession, or removal). The national day is often a public holiday.
Answer: There are 0.000043 moles of melatonin.
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number 
of particles.
To calculate the moles, we use the equation:
given mass = 10 mg = 0.01 g
molar mass of 
= 232.28 g
Thus there are 0.000043 moles of melatonin
Answer:
A communicable disease
Explanation:
Diseases that can be transferred are known as communicable diseases.
Answer:
pOH is 2.2
Explanation:
The pH scale goes from 0 to 14. As such, the pH and the pOH add up to 14. Subtract your pH from 14 to get your answer.
14 - 11.8 = 2.2
