The Periodic Table and Electron Shells Flashcards
(21 cards)
How are elements arranged in the modern periodic table?
In order of increasing atomic number.
What do the vertical columns in the periodic table represent?
Groups — elements with the same number of outer shell electrons.
What do the rows in the periodic table represent?
Periods — each new row represents a new electron shell.
What do elements in the same group have in common?
The same number of electrons in their outer shell and similar chemical properties.
What group are alkali metals in?
Group 1.
What group are halogens in?
Group 7.
What group are noble gases in?
Group 0
What is the rule for filling electron shells?
Electrons fill the lowest energy levels (shells) first.
How many electrons can the first, second, and third shells hold?
1st = 2, 2nd = 8, 3rd = 8.
What is the electronic configuration of nitrogen (atomic number 7)?
2.5
What does an atomic number tell you about an atom?
The number of protons (and therefore electrons in a neutral atom).
How can you tell how many shells an element has?
It’s the same as the period number.
How can you tell how many outer electrons an element has?
It’s the same as the group number.
What is the electronic configuration of sodium (atomic number 11)?
2.8.1
Where are metals found on the periodic table?
On the left side of the zig-zag line.
Where are non-metals found on the periodic table?
On the right side of the zig-zag line.
What are three properties of metals?
Conduct electricity, form basic oxides, high melting/boiling points.
What are three properties of non-metals?
Poor conductors, form acidic oxides, low melting/boiling points.
What is a defining property of noble gases?
They are inert (unreactive).
Why are noble gases unreactive?
They have full outer electron shells — very stable.
Do noble gases exist as molecules or atoms?
As single atoms (monatomic).
