A quick looks in the periodic table will show that aluminium has an atomic number equal to 13 . This means that any atom that is an isotope of aluminium will have 13 protons in its nucleus.
Subsequently, one may also ask, how many neutrons are there in aluminum?
The number of neutrons in an aluminum atom depends on the isotope. Al has the atomic number 13, that is it has 13 protons in the atom (Aluminium ). The most common and natural isotopes are Al27 and Al26 thus these atoms have 14 and 13 neutrons respectively (Isotopes of aluminium ).
What is the mass number of aluminum 27?
Mass number, A = no. of protons + no. of neutrons. Therefore, the number of neutrons in above isotope = A - Z = 27 - 13 = 14. Note: The molar mass of aluminium, which is average of atomic masses of all isotopes = 26.981538 g/mol, since 13Al27 is the major isotope.
How many electrons are there in an atom of aluminum?
So for the element of ALUMINUM, you already know that the atomic number tells you the number of electrons. That means there are 13 electrons in a aluminum atom. Looking at the picture, you can see there are two electrons in shell one, eight in shell two, and three in shell three.