# SCIENCE ;; Valence Electrons.

Helium is in group 18 of the periodic table. How is helium different from the other elements in this group?

A. Helium atoms have 2 valence electrons, while atoms of the other elements in the group all have 8 valence electrons.

B. Helium atoms have 2 electrons, while atoms of the other elements in the group all have 18 electrons.

C. Helium atoms have valence electrons in the first energy level, while atoms of the other elements in the group have valence electrons in the second energy level.

D. Helium atoms have a full outer energy level, while atoms of the other elements in the group do not have a full outer energy level. **

I picked D and wanted to know If I was correct.

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1. No, I disagree with D. I think A is correct.
He has two electrons in its outer shell while all of the other group 8 elements have 8 electrons in the outer shell. The outer shells of the elements in that group after Ne MAY have more than 8 but they don't. I think that makes A correct. As for D, He DOES have a full outer energy level so that is OK. The problem is the next statement. The other elements in the group hold 8 (and they MAY hold more) EXCEPT for Ne. Ne is 1s2 2s2 2p6 and that makes the outer energy level full for Ne but it makes the statement for D incorrect.

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DrBob222
2. slow,
Valence electrons 1 quick check
How many valence electrons does each atom of arsenic (As) have? Arsenic is element 33. It is in period 4 and family 15 (5A or the Nitrogen family) = 5
Two representative elements are in the same period of the periodic table. Which statement correctly describes the atoms of the two elements? = They have valence electrons in the same energy level.
Helium is in group 18 of the periodic table. How is helium different from the other elements in this group? = Helium atoms have 2 valence electrons, while atoms of the other elements in the group all have 8 valence electrons.
An emission spectrum will occur when ___. = An electron releases energy and falls back to a lower energy level.

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3. "you wrong" has the right answers 4/4! thanks!

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4. Helium atoms have 2 valence electrons, while atoms of the other elements in the group all have 8 valence electrons

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5. I think it is A becase in my book, it says that helium has 2 electrons in its outer shell while the other elements in the group have 8 in the outer shell.

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