1. All of the statements are true, but which could best be explained by electron-electron repulsion?
An electron is more difficult to remove from an atom of chlorine than an atom of phosphorus.
An electron is more difficult to remove from an atom of chlorine than an atom of iodine.
An electron is more difficult to remove from an atom of nitrogen than an atom of oxygen.
An electron is more difficult to remove from an atom of beryllium than an atom of boron.
2. All of the statements are true, but which could best be explained by a difference in effective nuclear charge?
An electron is more difficult to remove from an atom of chlorine than an atom of phosphorus.
An electron is more difficult to remove from an atom of chlorine than an atom of iodine.
An electron is more difficult to remove from an atom of nitrogen than an atom of oxygen.
An electron is more difficult to remove from an atom of beryllium than an atom of boron.