If an atom has 17 electrons and its mass number is 35, calculate the following: number of protons, atomic number, and number of neutrons.
6 years late but for anyone looking at this now...
the atomic number is 17
there are 17 protons
there are 18 neutrons
To calculate the number of protons, we use the atomic number of the atom. The atomic number is the number of protons in an atom, and it is also the number that determines an element's identity on the periodic table. Since you haven given us the number of electrons (17), the atom is neutral, meaning it has an equal number of protons and electrons. Therefore, the number of protons is also 17.
The atomic number is the number of protons (which we just found) and is the characteristic number of each element. So, for this atom, the atomic number is also 17.
To calculate the number of neutrons, we subtract the atomic number from the mass number. The mass number is the sum of protons and neutrons in an atom. In this case, the mass number is given as 35. Therefore, the number of neutrons can be calculated as follows:
Number of neutrons = Mass number - Atomic number
Number of neutrons = 35 - 17
Number of neutrons = 18
So, in summary:
Number of protons = 17
Atomic number = 17
Number of neutrons = 18