The Periodic Table Flashcards
(26 cards)
How are elements arranged in the periodic table?
According to their atomic number (proton number).
What are columns also known as?
Groups- everything in a single group has similar properties.
Why is the table called the periodic table?
Because similar properties occur at regular intervals.
Elements in the same group in the periodic table have…
the same number of electrons in their outer shell which gives them similar chemical properties.
Before the discovery of protons, neutrons and electrons how did they try to arrange elements?
According to their atomic weights.
What was wrong with early periodic tables?
They were incomplete as elements were placed in inappropriate groups if you were to follow the order of atomic weights.
What did Mendeleev do to overcome problems with the periodic table?
He left gaps for elements which hadn’t been discovered and in some places changed the order from atomic weights.
Why was Mendeleev mocked for his discoveries?
he came up with the law of octaves and people mocked him as he linked science to music
What made it possible to explain why the order based on atomic weights was not always correct?
The knowledge of isotopes.
Elements that react to form positive ions are…
Metals
Elements that form to make ions which are not positive are…
Non-metals
Where are metals found on the periodic table?
To the left and bottom of the periodic table
Where are non-metals found on the periodic table?
Towards the right and top of the periodic table.
What is group 0 also known as?
The Noble Gases
Noble gases are…
Unreactive and don’t easily form molecules as they have a full outer shell which makes them stable.
What can the group number tell us?
The amount of electrons an element has in it’s outer shell/
What increases as you go down the noble gases group?
The boiling points and increasing relative atomic mass
What is group 1 also known as?
the alkali metals
How many electrons do the alkali metals have in their outer shells?
1
When you go down group 1 what happens?
The reactivity of the elements increase.
What is group 7 also known as?
The halogens
How many electrons do halogens have in their outer shell?
7
Are halogens non-metals?
Yes
What do halogens consist of?
Molecules made of pairs of atoms
