The Periodic Table

Question 1

When did Dimitri Mendeleev publish his first periodic table?

Answer 1

1869

Question 2

What were the features of Mendeleev’s tables?

Answer 2

• he arranged them in order of increasing relative atomic mass
• then he arranged them by puttin those with similar properties below each other into groups
• he left gaps for yet to be discovered elements
• he switched the order of a few elements to keep the groups consistent

Question 3

How was Mendeleev able to predict the properties of undiscovered elements?

Answer 3

By looking at the chemical properties and physical properties of elements next to a gap

Question 4

How are the elements arranged in the modern periodic table?

Answer 4

The elements are arranged according to their atomic number - not their relative atomic mass

Question 5

In the periodic table the elements are arranged into:

Answer 5

• rows, called periods, in order of increasing atomic number

- vertical columns, called groups, where the elements have silo are properties

Question 6

Where are the metal elements found, and where are the non metal elements found?

Answer 6

Metal elements are found on the left hand side of the table and non metal elements are found on the right

Question 7

The positions of iodine and tellurium were reversed in Mendeleev’s table because:

Answer 7

• iodine has one naturally occurring isotope

- the most abundant tellurium isotopes are tellurium-128 and tellurium-130

Question 8

What is electronic configuration?

Answer 8

An electronic configuration is the way in which electrons are arranged in an atom

Question 9

How many electrons can the first shell, second shell and third shell hold?

Answer 9

First shell: max=2
Second shell: max=8
Third shell:max=8

Question 10

How do you predict electronic configuration?

Answer 10

It can be predicted from its atomic number. E.g sodium has an atomic number of sodium so:

• first shell= 2 electrons
• second shell= 8 electrons
• third shell=1 electron

Question 11

The electronic configuration of an element is related to its position on the periodic table. The links are:

Answer 11

• the number of circles in the electronic configuration of an element is represented in the periodic table as the period number that element is situated in
• the number of electrons in the outermost shell of an element is represented in the periodic table as the group number that element is situated in
• the number of electrons in an element is represented in the periodic table as the elements atomic number

Question 12

What do electronic configurations help explain?

Answer 12

The electronic configuration of atoms helps to explain the properties of elements and the structure of the periodic table