## kaylala Group Title Why do the knowledge of atomic number enable us to deduce the number of electrons present in an atom? one year ago one year ago

Atomic number is the number of protons in the nucleus and also the number of electrons in the electron cloud, but only when the atom has a neutral charge. $$\sf\huge\begin{matrix} 4\\\sf 2\end{matrix} He$$ 2 is the atomic number (the number of protons and the number of electrons (when the charge is neutral)) 4 is the mass number (the number of protons+neutrons)