Questions: Write the symbol of a period 3 element that forms a +3 cation.
Write the symbol of an ion from group 17 (7A) with 36 electrons.
Transcript text: Write the symbol of a period 3 element that forms a +3 cation.
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Part 2 of 3
Write the symbol of an ion from group 17 (7A) with 36 electrons.
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Solution
Solution Steps
Step 1: Identify Period 3 Elements
Period 3 elements are those in the third row of the periodic table: Na, Mg, Al, Si, P, S, Cl, and Ar.
Step 2: Determine Which Element Forms a +3 Cation
Among the period 3 elements, aluminum (Al) is known to commonly form a +3 cation (\( \text{Al}^{3+} \)).
Step 3: Identify Group 17 Elements
Group 17 elements, also known as halogens, include F, Cl, Br, I, and At.
Step 4: Determine the Ion with 36 Electrons
A neutral bromine (Br) atom has 35 electrons. To have 36 electrons, it must gain one electron, forming the bromide ion (\( \text{Br}^- \)).
Final Answer
For Part 1: \( \boxed{\text{Al}} \)
For Part 2: \( \boxed{\text{Br}^-} \)