The Periodic Table Flashcards
Give an example of an element Mendeleev predicted the properties of
Ekasilicon (germanium)
What is periodicity?
A repeating trend in properties of the elements
What is ionisation energy?
A measure of how easily an atom loses electrons
What is the first ionisation energy?
The energy required to remove one mole of electrons from one mole of gaseous atoms of an element
What factors affect ionisation energy?
Atomic radius - greater radius - easier
Nuclear charge - more protons - harder
Electron shielding - more - easier
What do ionisation energies provide evidence for?
Shells and sub shells
Why does ionisation energy decrease down a group?
The increased atomic radius and shielding outweigh the increase in nuclear charge
Why does the ionisation energy increase across a period?
Increased nuclear charge but no new she’ll
What are all metals except Mercury at room temperature?
Solids
Described metallic bonding
Each atom donates electron to be delocalised (sea) leaving a positive ion
The strong electrostatic attraction between the positive ions and electrons hold it together
Ions fixed in place maintaining structure
Delocalised electrons free to move
Why cab metals conduct electricity?
Sea of delocalised electrons can move and carry charge
What are the layers of graphite held together by?
Ldf
Who created the periodic table?
Mendeleev
