Question

What is the last element in Period $3$?

Answer 1

Hint: We know in the periodic table, a period is a row that comprises chemical elements. We have to know that all elements present in row could contain the same number of electrons present in their shell. The next element after each element could have more extra protons and will be less metallic compared to the previous element.

Complete answer:
We have to know that a period $3$ elements is one of the substance elements in the third line (or time) of the periodic table of the chemical elements. The periodic table is spread out in lines to delineate repeating (occasional) patterns in the chemical conduct of the elements as their atomic number expands: another line is started when the periodic table avoids a line and a chemical conduct starts to rehash, implying that elements with comparative conduct fall into similar vertical sections.
We have to know that the third period contains eight elements: sodium, magnesium, aluminum, silicon, phosphorus, sulfur, chlorine, and argon. The initial two, sodium and magnesium, are individuals from the s-square of the occasional table, while the others are individuals from the p-block. The entirety of the period $3$ elements happens in nature and has at any rate one stable isotope.
So, the last element that is present in Period $3$ is Argon.

Note:
We have to remember that in s-block as well as p-block of the periodic table, the elements found inside a similar period do not show any trend and property similarities. We also have to know that except argon all other elements would have application in biology and geology.