Based on the table, which atom has a charge of -1?

\begin{tabular}{|l|l|l|l|}
\hline Atom & Number of protons & Number of neutrons & Number of electrons \\
\hline 1 & 9 & 8 & 9 \\
\hline 2 & 9 & 9 & 8 \\
\hline 3 & 9 & 9 & 10 \\
\hline 4 & 9 & 10 & 9 \\
\hline
\end{tabular}

A. 1
B. 2
C. 3
D. 4



Answer :

To determine which atom has a charge of -1, we need to analyze the relationship between the number of protons and electrons for each atom.

Recall that:
- Protons are positively charged.
- Electrons are negatively charged.

The charge of an atom is determined by subtracting the number of protons from the number of electrons:
[tex]\[ \text{Charge} = \text{Number of electrons} - \text{Number of protons} \][/tex]

Let’s calculate the charge for each atom given in the table:

1. Atom 1:
- Number of protons: 9
- Number of electrons: 9
[tex]\[ \text{Charge} = 9 - 9 = 0 \][/tex]

2. Atom 2:
- Number of protons: 9
- Number of electrons: 8
[tex]\[ \text{Charge} = 8 - 9 = -1 \][/tex]

3. Atom 3:
- Number of protons: 9
- Number of electrons: 10
[tex]\[ \text{Charge} = 10 - 9 = 1 \][/tex]

4. Atom 4:
- Number of protons: 9
- Number of electrons: 9
[tex]\[ \text{Charge} = 9 - 9 = 0 \][/tex]

From the calculations, we see that Atom 2 has a charge of -1.

Therefore, the atom which has a charge of -1 is Atom 2.