History of Periodic Table

What was Dmitri Mendeleev's greatest contribution to the history of the periodic table?

• He arranged all of the known elements by their atomic number
• He realised that there was a pattern of reactivity which repeated every 8 elements
• He predicted the existence (and properties) of new elements
• He identified the "law of triads" which became the groups

Who arranged the first periodic table.

• Mosely
• Einstein
• Mendeleev
• Bohr

Mendeleev classified elements based on not only atomic mass but what else?                                                   

• reactivity
• boiling points
• physical properties only 
•  chemical & physical properties

Why were there blank spaces left in Mendeleev's periodic table?                                              

• He didn't know what to put there.
•  Undiscovered elements not yet known.
• Multiple elements could have fit
• He forgot to add the elements in.

Each column in the periodic table is called a 

• period
• group
• cluster
• unit

Particles in an atom's nucleus that are neutral and have no charge are 

• megatrons. 
• electrons.
• neutrons.
• protons. 

Tags

NGSS.HS-PS1-8

Rows in the Periodic Table are called

• Periods

• Groups/Families

• Cousins

• Metals

Tags

NGSS.HS-PS1-1

Column in the Periodic Table are called

• Periods

• Groups/Families

• Cousins

• Metals

The elements that touch the zigzag line on the Periodic Table are called

• metals

• nonmetals

• metalloids

• gasses

Tags

NGSS.HS-PS1-1

The three kinds of elements are

• metals, nonmetals, and liquid metals

• metals, nonmetals, and metalloids

• metals, solids, and liquids

• metalloids, asteroids, and nonmetals