EVERYDAY SCIENCE

Detailed explanation-1: -Mendeleev arranged the elements in order of increasing weight and broke them into rows such that elements in each column shared valence, the number of other atoms they combined with, as well as other properties.

Detailed explanation-2: -The chemical elements are arranged from left to right and top to bottom in order of increasing atomic number, or the number of protons in an atom’s nucleus, which generally coincides with increasing atomic mass.

Detailed explanation-3: -Mendeleev noticed that a pattern of properties appeared when he arranged the elements in order of increasing atomic mass. He found that some properties repeated regularly. For example, lithium, sodium, and potassium all react violently in water. Mendeleev lined up the cards for these elements to form their own group.

Detailed explanation-4: -(d) Increasing atomic masses Option (d) is the answer. According to Mendeleev’s Periodic Law, the elements were arranged in the periodic table in the order of increasing atomic numbers.

Detailed explanation-5: -Assuming there were errors in atomic masses, Mendeleev placed certain elements not in order of increasing atomic mass so that they could fit into the proper groups (similar elements have similar properties) of his periodic table.