| A | B |
|---|
| atomic radius | 1/2 the distance between two nuclei of 2 atoms of a diatomic molecule |
| cation | formed when an atom loses 1 or more electrons |
| anion | formed when an atom gains one or more electrons |
| shielding | occurs when core electrons block valence electrons from the pull of the nucleus |
| nuclear charge | the charge of all the protons in the nucleus |
| effective nuclear charge | the charge felt by valence electrons when shielding is taken into account |
| electronegativity | the ability of an atom in a compound to attract electrons |
| ionization energy | the energy required to remove an electron from a gaseous atom |
| atomic radius increases | down and to the left |
| electronegativity increases | up and to the right |
| ionization energy increases | up and to the right |
| shielding | increases down but remains constant across |
| metals tend to form these | cations |
| non metals tend to form these | anions |
| formed by losing 2 electrons | charge of +2 |
| formed by losing 1 electron | charge of 1+ |
| formed by gaining 1 electron | charge of 1- |
| formed by gaining 3 electrons | charge of 3- |
| cations | always smaller than the atoms they come from |
| anions | always larger than the atoms they come from |
| non metallic character | increases up and to the right |
| metallic character | increases down and to the left |
| adding additional electrons causes repulsion | the reason anions are larger than the atoms they come from |
| more positive charges than negative causes greater attraction to nucleus | the reason cations are smaller than the atoms they come from |
| the addition of more energy levels | the reason that atomic radius increases down a group |
| the addition of more protons and electrons so a stronger pull | the reason atomic radius decreases from left to right |
| fewer energy levels, so electrons are held more tightly to the nucleus | the reason the first ionization energy is greater moving up a group |
| valence electrons closer to an octet as moving right | the reason electronegativity increases right |
| less shielding so greater attraction to the nucleus | the reason electronegativity increases up |
| effective nuclear charge | stays the same down a group, but increases right |
| the number of valence electrons remains the same | the reason effective nuclear charge remains constant down a group |
| the addition of valence electrons | the reason effective nuclear charge increases right |
