periodicity 1.1 Flashcards
covalent radius
a measure of the size of an atom
covalent radius across the pt
atoms gain more protons in the nucleus meaning a greater nuclear charge, covalent radius decreases
why does the size of an atom decrease going across the pt
the outer electrons become more attracted to the nucleus and so are pulled in closer
covalent radius going down a group of the pt
more energy levels creates a shielding effect, covalent radius increases
why does the size of an atom increase going down a group of the pt
the outer electrons are shielded from the attraction to the nucleus so aren’t pulled in
ionisation energy
energy needed to remove one mole of electrons from one mole of gaseous atoms
ionisation energy across the pt
atoms gain more protons in the nucleus meaning a greater nuclear charge, ionisation energy increases
why does the ionisation energy increase going across the pt
electrons become more attracted to the nucleus, so more energy is required to remove them
ionisation energy going down a group of the pt
more energy levels creates a shielding effect, ionisation energy decreases
why does the ionisation energy decrease going down a group of the pt
the outer electrons are shielded from the attraction to the nucleus so less energy is required to remove them
electronegativity
a measure of an atoms attraction to the electrons in a bond
electronegativity across the pt
atoms gain more protons meaning a greater nuclear charge, electronegativity increases
why does the electronegativity increase across the pt
electrons in a bond become more attracted to the nucleus
electronegativity going down a group of the pt
more energy levels creates a shielding effect, electronegativity decreases
why does the electronegativity decrease going down a group of the pt
bonding electrons are shielded from the attraction to the nucleus
