SCIENCE
PHYSICAL SCIENCES
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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with the exception of helium which has 2, the remaining have 8 electrons in their outer energy levels
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they readily form positive ions
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their outermost energy level is missing one electron
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they can have either a positive or negative charge
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Detailed explanation-1: -The noble gases (Group 18) are located in the far right of the periodic table and were previously referred to as the “inert gases” due to the fact that their filled valence shells (octets) make them extremely nonreactive.
Detailed explanation-2: -Helium is in Group 8 (Nobel Gases) because its outer shell is full. The outer shell of helium is an s-type shell that can only hold two electrons. The rest of the Nobel Gases have a p-orbital that can hold 6 electrons.
Detailed explanation-3: -But group 2 elements have incompletely filled valence shell with 2 valence electrons. As helium possesses completely filled outer most shell (Duplet configuration) it is placed in group 18 not in group 2.
Detailed explanation-4: -Noble gases are the least reactive of all known elements. That’s because with eight valence electrons, their outer energy levels are full. The only exception is helium, which has just two electrons.