Question

part 4: fill in each arrow with the correct phrase
word bank: atomic radius decreases, atomic radius increases, ionization energy increases, ionization energy increases, electronegativity increases, electronegativity increases
periodic table of the elements

Explanation:

• Horizontal arrow (left - to - right):
• As we move from left to right across a period in the periodic table, the number of protons in the nucleus increases while the electrons are added to the same principal energy level. The increased nuclear charge pulls the electrons closer, so the atomic radius decreases. Also, it becomes more difficult to remove an electron (ionization energy increases) and the atom's ability to attract electrons (electronegativity increases) increases.
• Vertical arrow (top - to - bottom):
• As we move from top to bottom down a group, new electron shells are added. The outermost electrons are farther from the nucleus, so the atomic radius increases. The outermost electrons are more shielded from the nuclear charge, so it is easier to remove an electron (ionization energy decreases, but since the word - bank has "ionization energy increases" as an option for the upward direction, for the downward direction, if we consider the opposite of the upward trend where ionization energy increases as we go up, for the downward direction, the trend is the reverse. But since the word - bank has "atomic radius increases" for the downward vertical arrow. For the upward vertical arrow (opposite of downward), ionization energy increases (because electrons are closer to the nucleus and more tightly bound) and electronegativity increases (more effective nuclear charge felt by the outermost electrons as we go up a group).

Answer:

• Horizontal arrow (left - to - right): atomic radius decreases, ionization energy increases, electronegativity increases
• Vertical arrow (top - to - bottom): atomic radius increases
• Vertical arrow (bottom - to - top): ionization energy increases, electronegativity increases