Flashcards in C4c-The periodic table and covalent bonding Deck (15)
What are the two types of bonding?
-ionic bonding between metals and non metals
-covalent bonding between non metals
What is covalent bonding?
Sharing electron pairs
How do non metals combine together?
They form covalent bonds
Why do carbon dioxide and water have low melting points?
-simple molecular structures
-they have weak intermolecular forces which are easily parted from each other
Why don't carbon dioxide and water conduct electricity?
There are no free electrons or ions in molecular substances
What is a group of elements?
All the elements in a vertical column of the periodic table and have similar chemical properties
What does the group number say about the outer shell?
It is the same as the number of electrons in the outer shell
What is a period of elements?
All the elements in a horizontal row of the periodic table
What does the period of the element say about the number of shells?
The number corresponds to the number of occupied shells in the electronic structure
What is the order of the scientists who contributed to the understanding of the periodic table?
How did Döbereiner organise the elements?
-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
How did Newlands organise the elements?
Law of Octaves.
He arranged all the known elements into a table in order of relative atomic mass.
When he did this, he found that each element was similar to the element eight places further on.
Why was Newlands law of octaves criticised?
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.
How did Mendeleev organise the elements?
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..