Mendeleev - Development of the Periodic Table

Question 1

How did Mendeleev arrange the periodic table?

Answer 1

In order of incresing atomic weight

Question 2

What were 2 things no one but Mendeleev did?

Answer 2

1. He swtiched the order of specific elements so they fitted the pattern of other elements in the same group
2. He left gaps where an element was missing

Question 3

What did he predict for elements by his table?

Answer 3

He was able to predict the properties of undiscovered elements based on other elements in the same groups
* Able to predict if they were metals

Question 4

What is the difference between the periodic table now and Mendeleev’s version?

Answer 4

• The periodic table now is ordered by atomic number so protons - Protons were not discovered back then so Mendeleev ordered it by atomic weight
• The Noble Gases - these were not fully discovered when he published his table

Question 5

What is the term that describes how noble gases exist as single atoms?

Answer 5

Monoatomic

Question 6

Why does density increase as we move down Group 0 of the periodic table?

Answer 6

Relative atomic mass increases