$$\underline {Al} {H_3}$$ changes to $$AlH_4^-$$

$${H_2}\underline O $$ changes to $$H_3O^+$$

$$\underline N {H_3}$$ changes to $$NH_4^+$$

in all cases

NH₃, BF₄^-

NH₄⁺, BF₄^-

NH₃, BF₃

NH₂^-1, BF₃

s, p_x, p_y, d_xy

s, p_x, p_y, d_{x² - y²}

s, p_x, p_y, d_z²

s, p_x, p_y, d_yz

HF is less polar than HBr

absolutely pure water does not contain any ions

chemical bond formation takes place when forces of attraction overcome the forces of repulsion

in covalency transference of electron takes place