C4c-The periodic table and covalent bonding

Question 1

What are the two types of bonding?

Answer 1

• ionic bonding between metals and non metals

- covalent bonding between non metals

Question 2

What is covalent bonding?

Answer 2

Sharing electron pairs

Question 3

How do non metals combine together?

Answer 3

They form covalent bonds

Question 4

Why do carbon dioxide and water have low melting points?

Answer 4

• simple molecular structures

- they have weak intermolecular forces which are easily parted from each other

Question 5

Why don’t carbon dioxide and water conduct electricity?

Answer 5

There are no free electrons or ions in molecular substances

Question 6

What is a group of elements?

Answer 6

All the elements in a vertical column of the periodic table and have similar chemical properties

Question 7

What does the group number say about the outer shell?

Answer 7

It is the same as the number of electrons in the outer shell

Question 8

What is a period of elements?

Answer 8

All the elements in a horizontal row of the periodic table

Question 9

What does the period of the element say about the number of shells?

Answer 9

The number corresponds to the number of occupied shells in the electronic structure

Question 10

What is the order of the scientists who contributed to the understanding of the periodic table?

Answer 10

Döbereiner
Newlands
Mendeleev

Question 11

How did Döbereiner organise the elements?

Answer 11

• Triads s whi h consisted of a group of three elements which were similar to eachother in appearance and reaction.
• The middle elememt of each triad had a relative atomic mass that was the average of the other two

Question 12

How did Newlands organise the elements?

Answer 12

Law of Octaves.
He arranged all the known elements into a table in order ofrelative atomic mass.
When he did this, he found that each element was similar to the element eight places further on.

Question 13

Why was Newlands law of octaves criticised?

Answer 13

1) his groups contained elements that didn’t have similar properties. 2) He mixed up metals and non-metals. 3) He didn’t leave any gaps for the elements that hadn’t been discovered yet.

Question 14

How did Mendeleev organise the elements?

Answer 14

he arranged the elements in order of relative atomic mass.
But unlike Newlands he realised he had to leave gaps in order to keep elements with similar properties in the same vertical groups..

Question 15

How did further evidence confirm Mendeleev’s ideas about the periodic table?

Answer 15

• confirmation of his predictions about unknown elements

- how investigations on atomic structure agreed with his ideas.(way electrons are arranged in an atom)