To determine the values of a, b, and c in the table for the isotopes of hydrogen, we need to understand that:
- The number of protons in an atom determines what element it is. All isotopes of hydrogen have 1 proton.
- The number of neutrons plus the number of protons gives us the mass number of the isotope.
Let's analyze each isotope:
-
H-1 (Protium):
- Number of Protons: 1
- Number of Electrons: 1
- Number of Neutrons: 0
- Mass number = 1 (1 proton + 0 neutrons)
-
H-2 (Deuterium):
- Number of Protons: a (which is the same as for all hydrogen isotopes) = 1
- Number of Electrons: 1 (remains the same since it's neutral)
- Number of Neutrons: b
- Mass number = 2 (1 proton + b neutrons), therefore b = 1.
-
H-3 (Tritium):
- Number of Protons: 1
- Number of Electrons: 1 (remains the same since it's neutral)
- Number of Neutrons: c
- Mass number = 3 (1 proton + c neutrons), therefore c = 2.
Now we can fill in the values:
- a = 1 (for H-2)
- b = 1 (for H-2)
- c = 2 (for H-3)
So the final answers are:
- a = 1
- b = 1
- c = 2
Therefore, the correct answer is D. a = 1, b = 1, c = 2.