Question

According to Mendeleev’s Periodic Law, the elements were arranged in the periodic table in the order of:

• A. increasing atomic number
• B. decreasing atomic number
• C. increasing atomic masses
• D. decreasing atomic masses

Answer 1

The correct option is C

increasing atomic masses

Explanation:

Mendeleev’s periodic table:

• Mendeleev’s periodic table is an arrangement of elements in an increasing atomic mass order in a tablet form, such that it reflects similarities and trends in the behaviour of elements.
• Mendeleev’s periodic table can be understood better by reversing the arrangement of the elements.
• Here elements are, arranged in increasing order of atomic mass, in a horizontal line.
• This horizontal arrangement of elements is a ‘period’.
• When an element has high similarity to an earlier element, the new element is, placed just below the earlier element having similar properties to start a new period.
• The period’s one below the other form a ‘column’ (group). Thus, Mendeleev’s periodic table consists of horizontal rows and vertical columns or periods and groups, respectively.
• If the element is similar but not very much, it is, placed below but slightly away to differentiate it. Each column will have two sub-columns (A and B) such that elements in the same sub-columns show more resemblance.
• According to Mendeleev’s ′ Periodic Law, the elements were arranged in the periodic table in the order of increasing atomic masses.

Therefore, option (C) is correct.