How do you determine protons electrons and nuetrons in an element?

Answer 1

A Periodic Table is your best bet.

periodic tables can range in complexity but most will tell you the atomic number (located left upper corner) and the average Atomic Mass (right upper corner). with these two numbers you can work out protons and neutrons by realizing that the atomic numbers is = to # of proton and that because the proton and neutrons are ~1 amu in mass with electron have negliable mass

Average atomic mass - atomic number = # of neutrons

you will realize that this # is often not a whole number. that is because the same element (elements with same atomic number) may have different numbers of neutrons and the average atomic these are called isotopes. most elements will have a main isotope and some minor isotopes that makeup a same percentage of the total.

this is why you often see average mass of xx.99 like Cr which is 51.996 meaning that most of the isotopes will have a atomic mass of 52 (24 protons and 28 neutrons) and a relatively small percentage will have a mass of 51 (again 24 protons because it is still Cr but now 27 neutrons)

As for the number of electrons, this depends on what kind of chemistry the element is involved with. Just keep in mind that a neutrally charged molecule has the same number of + charges (protons) as - charges (electrons)

Answer 2

The number of protons in an element is the same as its atomic number, found on the periodic table. The number of electrons is also equal to the atomic number if the atom is neutral. Neutrons can be calculated by subtracting the atomic number from the atomic mass of the element.