Question #6b48e

Sep 7, 2017

$1 +$

Explanation:

When a neutral atom loses electrons, it becomes a positively charged ion, or cation, because the overall charge of an atom is given by

$\textcolor{b l u e}{\underline{\textcolor{b l a c k}{\text{net charge" = "no. of protons" - "no. of electrons}}}}$

As long as an atom has equal numbers of protons inside its nucleus and electrons surrounding its nucleus, it will be electrically neutral, .e. it will have a $0$ net charge.

Now, when an atom loses an electron, the number of electrons that surround the nucleus will decrease by $1$. This means that the atom will develop an overall $1 +$ charge.

For example, let's say that a neutral atom starts with $n$ protons inside its nucleus and $n$ electrons surrounding its nucleus. This atom is neutral because

$\text{net charge} = n - n = 0$

When this atom loses an electron, the number of electrons will go from $n$ to $n - 1$.

This time, the net charge will no longer be equal to $0$ because

$\text{net charge} = n - \left(n - 1\right)$

$\text{net charge} = \textcolor{red}{\cancel{\textcolor{b l a c k}{n}}} - \textcolor{red}{\cancel{\textcolor{b l a c k}{n}}} + 1$

$\text{net charge} = 1$

At this point, the atom becomes a cation that has an overall charge of $1 +$.

For a numerical example, take an atom of sodium, $\text{Na}$. This atom has $11$ protons inside its nucleus and $11$ electrons surrounding the nucleus. After it loses $1$ electron, it becomes a sodium cation, ${\text{Na}}^{+}$, which has an overall positive charge of $1 +$. 