Describe how mendeleev organized the elements into rows and columns in his periodic table.

The way how Mendeleev organized the elements into rows and columns in his periodic table was that he decided to arrange all the elements in rows in order of increasing mass, that will make the elements with similar properties stand  in the same column. Soon he discovered many new elements such as gallium and after that he realized how his periodic system is useful for classification new elements.

The answer is b; as a lab tech, you’re more behind the scenes and don’t interact with the patients.