Trends Flashcards
Atomic radius of an atom
Half the distance between the nuclei of 2 atoms of the same element that are joined together by a single covalent bond
First ionisation energy
Minimum energy required to completely remove the most loosely bound e from a neutral atom in its ground state
Eg NA(g) ->NA+(g) + e
Second ionisation energy
Energy required to completely remove an electron from an ion with 1 positive charge in the gaseous state
Eg Ca+ -> Ca+2 (g) + e
Exceptions of first ionisation energy
Any sub level that is completely or half filled has extra stability therefore it is harder to remove the electrons leading to a higher ionisation energy
Explain why x has a higher ionisation energy than y
Write e configuration of both
Compare e configuration
sublevels that are half filled or full have more stability
Why is second ionisation energy always bigger than the first
The e is removed from a positively charged ion
There is a greater attraction between the nucleus and the e being removed
thus more energy is require to move the e-
How does atomic radius differ down a group
Increases
Why does atomic radius increase down a group
Electrons are going into a new energy level
Increased shielding effect by inner e
How does atomic radius differ across a period
Decreases
Why does atomic radius decrease across a period
Increase in effective nuclear charge
No increase in shielding
How does first ionisation energy differ down a group
Decreases
Why does first ionisation energy decrease down a group
Increasing atomic radius
Increased shielding by inner electrons
How does first ionisation energy differ across a period
Increases
Why does first ionisation energy increase across a period
Increasing effective nuclear charge
Decreasing atomic radius
How does electronegativity differ down a group
Decreases
Why does electronegativity decrease down a group
Increasing atomic radius
Increased shielding by inner electrons
Why does electronegativity increase across a period
Increasing effective nuclear charge
Decreasing atomic radius
How does electronegativity differ across a period
Increases
why does x have an exceptionally high first ionisation energy?
write e- configuration
sublevels that are half full or full have extra stability
this makes it much harder to remove the most loosely bound e- and it requires much more energy
how do group 1 elements react?
by donating 1 e-