Which statement correctly describes an atom of the element helium?
A. An atom of helium has its valence electrons in it's first energy level.
B. An atom of helium most similarly behaves like an atom of hydrogen since it is in the same period.
C. An atom of helium has a full outer energy level and is therefore unusually reactive.
D. An atom of helium has eight electrons in its outer energy.
B is wildly wrong !!!
C is also Wildly wrong for the same reason. Hydrogen reacts. Helium reacts with essentially nothing because that first level is full of its two electrons
D is just crazy. Helium is our second element with two protons and two electrons.
The correct statement describing an atom of the element helium is:
D. An atom of helium has eight electrons in its outer energy.
To determine the correct answer, we need to understand the atomic structure of helium.
Helium is a chemical element with atomic number 2, which means it has 2 protons in its nucleus. In a neutral atom, the number of protons is equal to the number of electrons. Therefore, helium also has 2 electrons.
The electron configuration of helium is 1s2, where "1s" represents the first energy level (also called the 1s orbital) and is followed by the superscript "2" representing the two electrons in that orbital.
Since helium has only two electrons, it does not have a full outer shell like many other elements. The outermost energy level, or valence shell, is considered full when it contains 8 electrons. Only the noble gases (group 18 elements) have a full outer energy level. In the case of helium, its outer energy level is the first energy level, which can accommodate a maximum of 2 electrons.
Therefore, option D is the correct statement because helium has 2 electrons in its outer energy level, not 8, as stated in option D.