Mendeleev left several blank spaces in his original periodic table. what did those spaces represent? elements with unknown physical properties elements that did not fit into his pattern elements that had yet to be discovered elements with variable atomic masses

The Answer is the Mendeleev left several blanks in the periodic table for the elements that had yet to be discovered.
Periodic table is an arrangement of chemical elements in a table made up of rows and columns, rows are called periods and columns are known as groups.
In 1869, Dimitri Mendeleev who was a Russian Chemist published first organized periodic table.

A) the enthralling of formation for pure element in its standard state is always positivehope this : )