Question: how many atoms in total are present in one molecule of c7h5(no2)3?
Answer: For compounds with parentheses, it is necessary to count the number of atoms of each element carefully. That is, 1 mol of C7H5(NO2)3 contains 7 mol of C atoms, 5 mol of H atoms, 3 mol of NO2 (that is, 3 mol N atoms and 6 mol of O atoms).