Chapter 4 The Periodic Table

Question 1

In what order did Mendeleev originally arrange the elements in? Then changed it to what?

Answer 1

Mendeleev arranged the elements in order of increasing relative atomic mass then he arranged the elements by putting those with similar properties below each other int groups

Question 2

Why did Mendeleev leave gaps?

Answer 2

he left gaps for yet to be discovered elements

Question 3

What is an example of Mendeleev switching elements in order to fit the grouping system?

Answer 3

Even though Iodine has a smaller mass than
Tellurium, it was placed after Tellurium since it had similar
properties with other elements in group 7

Question 4

How are the elements arranged in the modern periodic table?

Answer 4

In the modern periodic table, the elements are arranged according to their atomic number - not their relative atomic mass.

Question 5

Compare and contrast the old and new periodic table. (5)

Answer 5

Both have groups and periods

Both have metals and non metals

Old had gaps, new did not

New has elements arranged as metals
and not metals, old had them mixed up

Old had elements arranged based on
mass number, new has them based on
atomic number

Question 6

What does the period number represent?

Answer 6

the number of shells in the electronic configuration of an element

Question 7

What does the group number represent?

Answer 7

the number of electrons in the outermost shell of an element

Question 8

How does the group number correlate to the properties of an element?

Answer 8

When atoms collide and react, it is the outer
electrons that meet and interact. So, elements in
the same group have similar chemical properties
because they have the same number of electrons
in their outer shell