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.
