To determine the number of nitrogen atoms present in one mole of serotonin (chemical formula [tex]\( C_{10}H_{12}N_2O \)[/tex]), we need to follow these steps:
1. Identify the number of nitrogen atoms in one molecule of serotonin:
From the chemical formula [tex]\( C_{10}H_{12}N_2O \)[/tex], we see that each molecule contains 2 nitrogen ([tex]\( N \)[/tex]) atoms.
2. Understand the concept of one mole:
One mole of any substance contains approximately [tex]\( 6.02 \times 10^{23} \)[/tex] units (atoms, molecules, etc.), which is known as Avogadro's number.
3. Calculate the total number of nitrogen atoms in one mole of serotonin:
Since one mole of serotonin contains [tex]\( 6.02 \times 10^{23} \)[/tex] molecules, and each molecule has 2 nitrogen atoms, we can calculate the total number of nitrogen atoms as follows:
[tex]\[
\text{Total nitrogen atoms} = 2 \times (6.02 \times 10^{23})
\][/tex]
4. Perform the multiplication:
[tex]\[
2 \times 6.02 \times 10^{23} = 1.204 \times 10^{24}
\][/tex]
Thus, the total number of nitrogen atoms in one mole of serotonin is [tex]\( 1.204 \times 10^{24} \)[/tex]. Therefore, the correct option is:
A. [tex]\( 1.2 \times 10^{24} \)[/tex] atoms