Abigail E. Sasuman
BS Civil Engineering, 1st Year
CHM012-B3
Assignment 5:
1. Explain why the graph of ionization energy versus atomic number (across a row)
is not linear.
Where are the exceptions?
-The ionization energy decreases down the group and increases along the period
from left to right, causing the graph of ionization energy vs. atomic number
nonlinear. As observed, discontinuities occur in going from beryllium to boron and
from nitrogen and from nitrogen to oxygen. These are the exceptions to the normal
trend.
2. Which of the following would require more energy to remove an electron? Why?
Sodium vs. Chlorine
-Sodium. It’s first ionization energy is one and one-half times larger than the
electron affinity for chlorine, which means it would require sodium more energy to
remove an electron from a neutral sodium atom than is given off when the electron
is picked up by a neutral chlorine atom.
Lithium vs. Cesium
-Lithium. Since Cesium has a lower ionization energy than lithium.
3. Which element has the larger second ionization energy? Why?
Lithium vs. Beryllium
-Lithium. In the first ionization energy, after removing the electron, beryllium will be
left with one valence electron, requiring low ionization energy, while lithium will
achieve noble gas configuration, requiring more energy in its second ionization
energy.
