PT: 10/03/2014 Flashcards
On the PT, a group goes from ____.
Top to bottom
On the PT, a period goes from ____.
Left to right
What are two synonyms for group?
Column, Family
What is a synonym for period?
Row
Valence
The number of electrons on the outermost energy level of an atom
Why is valence important?
It affects the way elements bond with each other.
If an element has a valence of 8…
It will not react
If an element has a valence of 1…
It will lose 1 electron
If an element has a valence of 2…
It will lose 2 electrons
If an element has a valence of 3…
It will lose 3 electrons
If an element has a valence of 4…
It will either gain or lose electrons (because 4 is half way to 8)
If an element has a valence of 5…
It will gain 3 electrons to fill its outer energy level to 8
If an element has a valence of 6…
It will gain 2 electrons to fill its outer energy level to 8
If an element has a valence of 7…
It will gain 1 electron to fill its outer energy level to 8
What was wrong with Mendeleev’s periodic table?
The pattern in atomic mass did not always increase from left to right. There were a few inconsistencies that would have caused elements to be grouped with elements that did not have similar properties.
