1 mol of any particles has 6.02 * 10 ²³ particles.
If we look at 1 NH3 (1 mol NH3 or 1 molecule NH3), we can see that 1 molecule NH3 has 1 atom of N and 3 atoms of H; also 1 mole of NH3 has 1 mole of N atoms and 3 moles of H atoms.
So, 1 mol of NH3 has 1 mol of N atoms,
and 2.79 mol NH3 have 2.79 mol of N atoms.
2.79 mol of N atoms* 6.02 * 10 ²³ N atoms/ 1 mol N atoms = 1.68*10²⁴ N-atoms
Answer is 1.68*10²⁴ N-atoms.
A. p block
from 3a-8a are in the p block including halogen
Question is incomplete, complete question is;
A 34.8 mL solution of
(aq) of an unknown concentration was titrated with 0.15 M of NaOH(aq).

If it takes 20.4 mL of NaOH(aq) to reach the equivalence point of the titration, what is the molarity of
? For your answer, only type in the numerical value with two significant figures. Do NOT include the unit.
Answer:
0.044 M is the molarity of
(aq).
Explanation:
The reaction taking place here is in between acid and base which means that it is a neutralization reaction .
To calculate the concentration of acid, we use the equation given by neutralization reaction:

where,
are the n-factor, molarity and volume of acid which is 
are the n-factor, molarity and volume of base which is NaOH.
We are given:

Putting values in above equation, we get:

0.044 M is the molarity of
(aq).
Answer:
It has its elements with mass numbers phrased in many decimal places, it requires one to round off to get the actual value.
The atomic numbers of some elements such as Protonium were just guessed.
Answer: Option (d) is the correct answer.
Explanation:
When two or more different substances are mixed together then it results in the formation of a mixture.
Mixture are of two types, that is, homogeneous mixture and heterogeneous mixture.
In homogeneous mixture, the constituent particles are distributed evenly throughout the mixture.
Whereas in heterogeneous mixture, the constituent particles are non-uniformly distributed.
Thus, we can conclude that mixtures are classified based on the distribution of particles in them.