1(d) - The Periodic Table Flashcards
How are elements in the periodic table arranged? How do YOU remember them?
The elements in the Periodic Table are arranged in order of increasing atomic number.
Columns are called Groups. They indicate the number of electrons in the outer shell of an atom.
Rows are called Periods. They indicate the number of shells (energy levels) in an atom.
(Common ground and red pears)
Rules for working out the arrangement (configuration) of electrons:
- Example – chlorine (Cl)
1) Use the periodic table to look up the atomic number. Chlorine’s atomic number (number of protons) is 17.
2) Remember the number of protons = number of electrons. Therefore chlorine has 17 electrons.
3) Arrange the electrons in levels (shells):
- 1st shell can hold a maximum of 2
- 2nd can hold a maximum of 8
- 3rd can also hold 8
Therefore the electron arrangement for chlorine (17 electrons in total) will be written as 2,8,7
4) Check to make sure that the electrons add up to the right number
The electron arrangement can also be draw in a diagram.
How do you classify an element as a metal?
- conduct electricity
- have oxides which are basic (alkaline), reacting with acids to give a salt and water
How do you classify an element as a non-metal?
- do not conduct electricity (except for graphite)
- have oxides which are acidic or neutral
Where are metals, nonmetals and semimetal positioned on the periodic table?
Metals on the left of the Periodic Table.
Non-Metals on the top-right, plus Hydrogen.
How is the electronic configuration of a main group element is related to its position in the Periodic Table?
Elements in the same group have the same number of electrons in their outer shell. This is why elements from the same group have similar properties.
Why do elements in the similar chemical properties?
Elements in the same group of the periodic table have the same number of electrons in their outer shells, which means they have similar chemical properties.
Why do noble gases not readily react?
The noble gases are inert (unreactive) because they have a full outer shell of electrons.
