periodicity Flashcards
how are elements arranged in the periodic table ?
in order of increasing atomic number
Li-Ca
metallic
H-S
covalent molecular
B-C
covalent network
the covalent radius is…
a measure of size of an atom
going across a period the covalent radius…
decreases due to an increased nuclear charge experienced by the electrons causing them to be pulled tighter to the nucleus
going down the groups the covalent radius
increases as there are more electron shells
the first ionisation energy is…
the energy required to remove one mole of electrons from one mole of gaseous atoms.
going across a period ionisation energy…
increases due to increased nuclear charge resulting in electrons being more strongly attracted to the nucleus thus needing more energy to be removed
going down a group ionisation energy…
decreases due to increased electron shielding making the electrons less strongly attracted to the nucleus thus less energy is required to remove them.
electronegativity is…
a measure of the attraction of an atom involved in a bond has for the electrons of the bond
going across periods electronegativity….
increases as atoms have an increased nuclear charge meaning the nucleus will attract the bonding electrons more strongly
going down groups electronegativity…
decreases due to electron shielding the electrons are not as strongly attracted to the positive nuclei.
