Question

what is the main characteristic of the last element in each period of the periodic table?what is the general name of such elements

Answer 1

The last elements in each period of the periodic table have complete outermost electrons. They have 8 valence in their outermost shell. They are very unreactive as they are very stable. These elements are called as Noble gas elements or zero group elements.

Answer 2

Hi.

Here is your answer---

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The last elements of the each periods of the Periodic Table collectively forms a group. The group number of this group is 18 or VIII. 

The elements of this Group is known as Noble Gases or Inert Gases.

These gases are---

@---Helium
@---Neon
@---Argon
@---Xenon
@---Krypton
@---Radon
@---Organesson

[Note---Organesson is an Synthetic Elements which is denoted by the Symbol Og. It has a chemical Properties similar to noble gases, hence it is placed in there Groups.It was First Synthesized at the Joint Institute in Dubna, Russia for nuclear Research. It has an Atomic Number 118 and Atomic mass 294 u.]

The Characteristics of the Group 18 are---

# The elements of this Group are Un-reactive.

# They are gaseous in nature.

# They have there octet Complete,i.e. they have eight electrons in there valence shells {Exception : Helium, This gas has its Duplet completed}

# They conducts Electricity.

#They are odorless and colorless.

# The elements of this group are mono atomic.

The General name given to them are Noble Gases or Inert Gases.

They are called as Noble gases because they do not reacts with any elements.

They are called as Inert gases because they are unable to form compounds as they don't reacts with other elements.

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Hope it helps.

Have a nice day.