To determine the number of protons, neutrons, and electrons in a gallium ion with a +3 charge, we start with the basic information about gallium:
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The atomic number of gallium (Ga) is 31, which means it has 31 protons.
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The mass number is 70, which accounts for the total number of protons and neutrons. To find the number of neutrons, we can use the formula:
\[ \text{Neutrons} = \text{Mass number} - \text{Atomic number} = 70 - 31 = 39 \]
So, gallium has 39 neutrons.
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An ion with a +3 charge means it has lost 3 electrons. In a neutral gallium atom, the number of electrons is equal to the number of protons, which is 31. Therefore, for a gallium ion with a +3 charge:
\[ \text{Electrons} = \text{Protons} - 3 = 31 - 3 = 28 \]
Now we can summarize the counts:
- Protons: 31
- Neutrons: 39
- Electrons: 28
Based on this information, the correct response from the options provided is:
Particle Number
protons 31
neutrons 39
electrons 28