Question

Elements are arranged in order of increasing _____ ______ in the modern periodic table; the concept however was unknown at the time of Mendeleev (2 words).

Answer 1

Elements in the modern periodic table are arranged in order of increasing atomic number.

Step-by-step explanation:

The elements in the modern periodic table are arranged in order of increasing atomic number.

This concept was unknown at the time of Mendeleev, who initially arranged the elements based on their atomic masses.

However, it was later discovered that the periodic relationship among the elements is based on their atomic numbers.

The atomic number refers to the number of protons in the nucleus of an atom.