Structure 3.1

repeating trends in the physical and chemical properties of elements across a period and down a group

copper chromium

the positive charge possessed by the nucleus of an atom (i.e. number of protons in the nucleus of an atom)

increases, as there are more protons in the nucleus of successive elements down the group

increases, as there are more protons in the nucleus of each successive element across the grou

the reduction in attractive force experienced by electrons in the valence shell due to the presence of inner shell electrons

increases, as the number of occupied electron shells increases, increasing the shielding effect

remains constant, as electrons are only added to the valence shell. the number of inner electrons constant. therefore, the shielding effect is constant.

attractive force experience by the electrons in the valence shell

ENC = nuclear charge - number of shielding electrons

effective number charge number of occupied electron shells (i.e. distance of the valence shell from the nucleus) repulsion between electrons

remains the same

increases. number of protons increase, but number of shielding electrons remain the same therefore, the effective nuclear charge will increase

atomic radii ionisation energy electron affinity electronegativity ionic radius

distance from the nucleus to the valence shell of an atom

half the distance between neighbouring nuclei of the same element

increases. effective nuclear charge remains constant down a group. more electron shells are occupied. therefore, the distance between valence electrons and the nucleus increases

decreases. effective nuclear charge increases with each successive element. number of shielding electrons (