The maximum number of electron in this atom with the mentioned quantum number is 2.
Work Step by Step
*NOTES TO REMEMBER: - The maximum number of electrons which can occupy an orbital is 2. - The number of orbitals in a subshell depends on the type of subshells: +) Subshell $s$: $l=0$, so $m_l=0$. Therefore, 1 orbital. +) Subshell $p$: $l=1$, so $m_l=-1,0,1$. Therefore, 3 orbitals. +) Subshell $d$: $l=2$, so $m_l=-2,-1,0,1,2$. Therefore, 5 orbitals. +) Subshell $f$: $l=3$, so $m_l=-3,-2,-1,0,1,2,3$. Therefore, 7 orbitals. $n=4$ means we are referring to the fourth shell. $l=1$, that means we are talking about the subshell $4p$. Subshell $4p$ has 3 orbitals, with $m_l$ ranging from $-1$ to $1$. However, since they already gave $m_l=0$, we only consider only 1 specific orbital: $4p$ with $m_l=0$. Two electrons in maximum can occupy an orbital. Since there is only 1 orbital here, the maximum number of electrons possible in this atom is 2.