Video Transcript
Hydrogen-1 has an atomic number of
one. How many neutrons are there in an
atom of hydrogen-1?
To answer this question, we need to
determine how many neutrons, neutrally charged particles found in the nucleus, are
in an atom of hydrogen-1. We are given the atomic number of
hydrogen. The atomic number can be used to
distinguish one element from another as all 118 known elements have a different
atomic number. The atomic number also indicates
the number of protons in the nucleus of all atoms, ions, and isotopes of that
element. As hydrogen-1 has an atomic number
of one, an atom of hydrogen-1 must contain one positively charged proton.
Atoms have an overall neutral
charge. If an atom of hydrogen-1 contains
one positively charged proton, then it must contain one negatively charged electron
in order to be electrically neutral.
With this information alone, we
still don’t know the number of neutrons in the atom. But the question tells us that we
are working with an atom of hydrogen-1. The one written after the name is
the mass number of the atom. The mass number is the total number
of protons and neutrons in the nucleus of an atom, ion, or isotope. The atom of hydrogen-1 has a mass
number of one and one proton.
Rearranging to solve for the number
of neutrons, we find that this atom has zero neutrons. So the number of neutrons in an
atom of hydrogen-1 is zero.
