Trends in the periodic table Flashcards
Atomic radius
Half the distance between 2 nuclei of the same element that are joined by a single covalent bond
Factors affecting trends in the P Table
Nuclear charge
Shielding effect
Loosely bounded electron
Across a period
Radius decreased:
An increase in the nuclear charge
No change in the shielding effect
Down a group
Atomic radius will increase:
The outermost electron is occupying an energy level further from the nucleus
There is an increase in the shielding effect
First ionisation energy
The minimum amount of energy required to remove 1 mole of the most loosely bounded electrons from one mole of atoms in their neutral gaseous, ground state.
IE across a period
Increases:
Increasing nuclear charge
Decrease in atomic radius
No change in shielding effect
IE down a group
Decreases:
The outermost electron occupies an energy level further from the nucleus
There is an increase in the shielding effect
2nd Ionisation energy
The minimum energy required to remove 1 mole of the second most loosely bonded electron from 1 mole of atoms in their gaseous, ground, +2 charged state
Successive ionisation energy
Always increase. Depending on electronic configuration some increases are greater than others,
As electrons are taken away electrons there are still the same number of protons, but not attracting even less electrons, thus holding them tighter.
Electronegativity
The relative attraction an atom has for the shared pair of electrons in a single covalent bond
Scale by Linus Pauling
Electronegativity trend
Across a period
Increases:
Increasing nuclear charge
Decreasing atomic charge
No change in the shielding effect
Electronegativity trend
Down a group
Decreases:
Energy level where the electron is filling is further from the nucleus
The screen effect increases
