Step-by-step explanation:
We are given different isotopes and we have to identify the number of protons and neutrons that are in the nuclueus of each atom.
a) Carbon-14:
By definition two isotopes are atoms that have the same atomic number but different mass number. The atomic number of an atom is equal to the number of protons of that atom, and the mass number is equal to the number of protons plus the number of neutrons.
atomic number = n° of protons
mass number = n° of protons + n° of neutrons
n° of protons = atomic number
n° of neutrons = mass number - n° of protons
n° of neutrons = mass number - atomic number
If two isotopes have the same atomic number but different mass number we can say that two isotopes have the same number of protons but different number of neutrons.
In we pay attention to carbon-14 we can look for its atomic number in the period table: 6. And its mass number is the one that we are given after the name of the element: 14.
n° of protons = atomic number = 6
n° of protons = 6
n° of neutrons = mass number - atomic number = 14 - 6
n° of neutrons = 8
b) Cobalt-60:
atomic number = 27 (from the periodic table)
mass number = 60
n° of protons = atomic number = 27
n° of protons = 27
n° of neutrons = mass number - atomic number = 60 - 27
n° of neutrons = 33
c) Gold-197:
atomic number = 79 (from the periodic table)
mass number = 197
n° of protons = atomic number = 79
n° of protons = 79
n° of neutrons = mass number - atomic number = 197 - 79
n° of neutrons = 118
d) Uranium-235:
atomic number = 92 (from the periodic table)
mass number = 235
n° of protons = atomic number = 92
n° of protons = 92
n° of neutrons = mass number - atomic number = 235 - 92
n° of neutrons = 143
Answer:
a) Carbon-14: n° of protons = 6 n° of neutrons = 8
b) Cobalt-60: n° of protons = 27 n° of neutrons = 33
c) Gold-197: n° of protons = 79 n° of neutrons = 118
d) Uranium-235: n° of protons = 92 n° of neutrons = 143