An atom of barium-130 has 56 protons and 74 neutrons. This can be derived from the atomic number and the mass number of the element.
Barium (Ba) has an atomic number of 56, which means that every atom of barium has 56 protons in its nucleus. The mass number of barium-130 indicates that the total number of protons and neutrons in the nucleus is 130.
To find the number of neutrons, we can use the formula:
Number of neutrons = Mass number – Number of protons
Substituting the values, we have:
Number of neutrons = 130 – 56 = 74
Thus, in summary, a barium-130 atom contains 56 protons and 74 neutrons.