Chemistry Question on Modern Periodic Law And The Present Form Of The Periodic Table

Question

The element with the atomic number 118, will be

Answer 1

Solution

The correct option is (b) noble gas

Explanation:

The outermost electronic configuration of an element with atomic number 118 is 7s27p6. Since its electronic configuration in the outermost orbit, ns2np6 resembles inert or noble gases therefore it will be a noble gas element.

The electronic configuration of an element with atomic number 118 will be [Rn]5f146s26p6. The element with the atomic number 118, will be a noble gas.

Alternate Approach

Elements with different atomic numbers have different electronic configurations that enables us to understand the positions of these elements in the periodic table. A periodic table contains elements grouped in different blocks such as s, p, d, and f.

Complete answer:

The atomic number of an element of a chemical element is the number of electrons present in the neutral species.

Electronsof an atom or molecule distribute themselves in an atomic or molecular orbital.
This distribution refers to electronic configuration.
The electronic configuration provides an insight into the chemical behaviour of elements and their position in the periodic table.

Characteristics of noble gases

Noble gases are odourless, non-flammable, colourless, and monoatomic gas with low chemical reactivity.

All the noble gases conduct electricity and fluorescence which can be needed in many conditions to maintain a constant and safe environment.
All noble gases are insoluble in water.
As they have a complete octet which makes them highly stable. So, they hardly react with other elements to form chemical bonds because of their low tendencies to either gain or lose electrons.
But exceptions are everywhere. Xenonis a noble gas that may form compounds either with fluoride or oxide

Further the important steps for determining electronic configuration we

Shells: Electronic configuration of an element with atomic number will be [Rn]5f146d167s27p6.
Subshells: Its electronic configuration in the outermost orbit (ns2np6)
Notations: This resembles that of inert or noble gases such as Argon[Ne]3s23p6.

Thus, it will be a noble gas element. Therefore, option (B) is the correct option i.e. Noble Gas.

Note: Note that we also analyze and solve the question by considering Radon which is a noble gas, also which has atomic number 86 When 32 electrons are added to it, we get the element with atomic number 118. Since, in the seventh period, a maximum of 32 electrons can be accommodated. Hence, an element with atomic number 118 is a noble gas.