Respuesta :

Helium is found in the 1st period of the periodic table. It also is part of the noble gases group in the last column (18th) of the table.
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Answer:

Period no. = 1, Group no. = 18

Explanation:

Atomic number of He = 2

Helium is placed in period 1 and group 18.

Helium is an inert gas and also known noble gas.

Helium is the first element placed in group 18.

Helium is a colourless, odder-less gas. Its outer shell (K shell) is fully occupied and so has inert gas configuration.

Because of inter gas configuration, it is chemically inactive.

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