The Periodic Table

Question 1

How is the modern periodic table organised?

Answer 1

Elements are arranged in order of increasing atomic number.
The horizontal rows are called periods and the vertical columns are called groups.
Elements in the same group have similar chemical properties

Question 2

How did Mendeleev organise his periodic table?

Answer 2

Mendeleev arranged the elements in order of increasing relative atomic mass.
When he did this he noted that the chemical properties of the elements and their compounds showed a periodic trend.
He then arranged the elements by putting those with similar properties below each other into groups.

Question 3

What else did Mendeleev do to his periodic table?

Answer 3

To make his classification work Mendeleev made a few changes to his order:
He left gaps for yet to be discovered elements
He switched the order of a few elements to keep the groups consistent

Question 4

Why did Mendeleev leave gaps?

Answer 4

Mendeleev left gaps in his table to place elements not known at the time. By looking at the chemical properties and physical properties of the elements next to a gap, he could also predict the properties of these undiscovered elements

Question 5

What is electronic configuration?

Answer 5

Arrangement of electrons within an atom
Max 2 in the first shell
Max 8 in the second
Max 8 in the third

Question 6

How does the electronic configuration relate to an element PERIOD on the periodic table?

Answer 6

the number of circles in the electronic configuration of an element is represented in the periodic table as the period

Question 7

How does the electronic configuration relate to an element GROUP NUMBER on the periodic table?

Answer 7

the number of electrons in the outermost shell of an element is represented in the periodic table as the group number