EVERYDAY SCIENCE

Detailed explanation-1: -Elements that are not main group elements are the transition metals (such as titanium, copper, and gold), the lanthanides (such as lanthanum and erbium), and the actinides (such as actinium and plutonium).

Detailed explanation-2: -Argon is a chemical element with symbol Ar and atomic number 18. Classified as a noble gas, Argon is a gas at room temperature.

Detailed explanation-3: -In chemistry and atomic physics, the main group is the group of elements (sometimes called the representative elements) whose lightest members are represented by helium, lithium, beryllium, boron, carbon, nitrogen, oxygen, and fluorine as arranged in the periodic table of the elements.