What were the criteria used by mendeleev in creating his periodic Table?

besides gallium, which other elements have since been discovered that were left by Mendeleev in his periodic Table?

What is time period?

Describe the criteria used in the fivekingdom classification.

What property do all elements in the same column of the periodic Table as fluorine have in common?

What property do all elements in the same column of the periodic Table as boron have in common?

What are the criteria you would consider when trying to categorise something as a good fuel ?

Define Mendeleev's Periodic Law