Final answer:
Gallium (Ga) has 31 protons, as its atomic number is 31. This is also the number of electrons in a neutral atom of Gallium. By comparison, a neutral atom of nickel (Ni) has 28 protons and electrons.
Step-by-step explanation:
The number of protons in an atom of an element is given by its atomic number. In the case of Gallium (Ga), we can find its atomic number on the periodic table, which is 31.
This means that an atom of gallium contains 31 protons. This atomic number is also indicative of the number of electrons in a neutral atom of Gallium, which would also be 31.
In comparison, the atomic number of nickel (Ni) is given as 28, hence, a nickel atom contains 28 protons and, if neutral, also 28 electrons. A specific nucleus of uranium mentioned has 92 protons and 146 neutrons, indicating that different elements have different numbers of protons, unique to each element.