Where did Mendeleev arrange the elements in the periodic table with similar properties?

Correct option is A

The correct answer is (a) Vertical column

Explanation:

• Mendeleev arranged the elements in the periodic table in vertical columns (also known as groups), where elements with similar properties were placed in the same column.
• This arrangement was based on the atomic masses of the elements. Mendeleev noticed that elements with similar chemical behaviors appeared at regular intervals, so he placed them in columns accordingly.
• The periodic law, based on Mendeleev’s table, states that the properties of elements are a periodic function of their atomic masses.

Information Booster:

• Mendeleev’s arrangement was instrumental in the development of the periodic table. He left gaps for undiscovered elements and predicted their properties, which was later confirmed with the discovery of new elements.
• Elements in the same group (vertical column) of the periodic table share similar chemical properties, such as the alkali metals (Group 1) or halogens (Group 17).

Additional Knowledge:
(b) Atomic series: This term is not related to how Mendeleev arranged the elements.
(c) Horizontal row: In Mendeleev's periodic table, elements were arranged in horizontal rows (called periods), but it is the vertical columns (groups) that grouped elements with similar properties.
(d) Block: This term is not used in Mendeleev's original periodic table; blocks are a later concept used in modern periodic tables based on electron configurations.