Question

The elements with atomic numbers 2, 10, 18, 36, 54 and 86 are all __________.
a.) Light metals
b.) Halogens
c.) Rare earths
d.) Noble gases

Answer 1

In order to solve the given problem first we will understand the basic structure of a periodic table further we will see the fundamental characteristics kept under consideration behind the arrangement of such periodic tables. We will discuss the properties of periods and groups in a periodic table further we will find out the group to which these elements belong and further we will also discuss in brief about the properties and uses of these elements.

Complete step by step answer:
In accordance with their increasing atomic number and repeated chemical properties, the periodic table is an arrangement of all the elements known to man. In a tabular arrangement in which a row is a time and a column is a group, they are assorted.
A new and updated iteration of some versions put out by scientists in the 19th and 20th centuries is the modern periodic table, the one we have today. Centered on the observations of several scientists before him, such as John Newlands and Antoine-Laurent de Lavoisier, Dimitri Mendeleev proposed his periodic table. However, for his invention of the periodic table, Mendeleev is given sole credit.
Elements are grouped in the order of their increasing atomic numbers, from left to right and top to bottom. Accordingly,
Elements in the same group may have the same structure of the valence electron and hence identical chemical properties.
Whereas, elements would have a growing order of valence electrons in the same time. Therefore, as the atom's energy level grows, the amount of sublevels of energy per level of energy grows.
The vertically arranged each row in the table are the groups of the periodic table in which certain elements are arranged with increasing atomic number from top to bottom.
The elements in the same group have the same number of valence electrons in their outermost energy level and due to this feature they have similar chemical properties.
The elements with atomic numbers 2, 10, 18, 36, 54 and 86 have completely filled valence orbital and so they belong to the last group or the zero group of the periodic table.
These elements are inert gases or noble gases. The zero group of the periodic table of Mendeleev or group 18 of the long version of the periodic table consists of six elements and these elements are considered inert gases because these elements do not react (inert) with other elements due to their stable structure of the outer electronic configuration of the octet.
Hence, the elements with atomic numbers 2, 10, 18, 36, 54 and 86 are all noble gases.
So, the correct answer is “Option D”.

Note: In order to solve such types of problems students must remember different types of periodic tables that were proposed and the developments made in each one and also the characteristics and the features of the modern periodic table. Also the students must know about the relation between the elements which lie in the same horizontal row of the periodic table that they have a similar number of atomic orbital for electrons.