It’s
1.A
2.C
3.B
hope it’s correct
A carbon-12 atom has 6 protons (6P) and 6 neutrons (6N). But some types of carbon have more than six neutrons. We call forms of elements that have a different number of neutrons, isotopes. For example, carbon-14 is a radioactive isotope of carbon that has six protons and eight neutrons in its nucleus.
Hope that helps
Answer: The empirical formula is
.
Explanation:
Mass of C = 1.71 g
Mass of H = 0.287 g
Step 1 : convert given masses into moles.
Moles of C = 
Moles of H = 
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For C =
For H =
The ratio of C: H = 1: 2
Hence the empirical formula is
.
The correct answer is A) the number of electrons that fill the outer shell.
Brady