Answer Key for Periodic Trends Practice
8. O C
Be
Ne
Electronegativity
Neon has the lowest electronegativity because it does not desire to gain any more electrons. Oxygen has
a higher electronegativity than carbon and beryllium because it has more protons, which results in
higher Coulomb’s forces and a greater desire to gain electrons
9. Na Rb Fr
H
Atomic radius
Hydrogen would have the smallest atomic radius of these elements. Francium has the largest atomic
radius because it has the most energy levels shielding the single outer electron from the pull of the
nucleus.
10. Na Rb Fr
H
Ionization energy
Of the group one elements, Francium has the lowest ionization energy because the outer electron is
farther away from the nucleus than the other elements, which means the Coulomb’s forces holding the
electron in place are very weak, making it very easy to remove the electron.
11. Skip this question
12. Na Rb Fr
H
Electronegativity
Of the group one elements listed here, Hydrogen would have the highest electronegativity because the
electrons are closer to the nucleus, which increases the chances of gaining an electron because the
nucleus has a greater pull on the electron cloud than the other larger elements.
13. Pb
C
Sn
Si
Largest Atomic Radius
Lead (Pb) would have the largest atomic radius because it has the most electron energy levels protecting
the outer electrons from the pull of the nucleus.
14. Pb
C
Sn
Si
Ionization energy
The element in this group with the highest ionization energy would be carbon because it has the fewest
electron energy levels, which results in higher Coulomb’s forces holding the outer electron in place. Due
to the decreased distance between the outer electron and the nucleus, it would require more energy to
take the electrons away from carbon
15. Skip this question
Answer Key for Periodic Trends Practice
16. Pb
C
Sn
Si
Electronegativity
Carbon would have the highest electronegativity of these elements because it has the fewest number of
shielding electrons, which allows the nucleus of this element to attract electrons more readily than the
larger elements in the group below it.
17. Au W S
Fr
Ne
Zn
Largest Atomic radius
Francium would have the largest atomic radius because it has the highest number of electron energy
levels. The large number of electrons present in the electron cloud would not only shield the outer
electron from the pull of the nucleus, but also repel each other and cause the electron cloud to spread
out more.
18. Au W S
Fr
Ne
Zn
Ionization energy
Due to increased Coulomb’s forces and a low number of electron energy levels, neon would have the
highest ionization energy, which means it would be harder to pull an electron away from this nucleus
than any other element listed here.
19. Skip this question
20. Au W S
Fr
Ne
Zn
Electronegativity
Sulfur would have the highest electronegativity and the greatest desire to gain electrons because it has
the lowest number of electron energy levels and the highest effective nuclear charge. The closer the
electrons are to the nucleus, the more likely the element will be desirous to gain electrons. Gold,
tungsten, francium, and zinc are all metals, which have the tendency to lose electrons, and neon does
not desire to gain electrons because it has a full outer electron shell, and thus no measurable
electronegativity.
21. Elements with smaller ionic radius than the neutral atom: Na+ Sr+ Cr3+ C4+ Ag+
Cations (positively charged ions) have a reduced atomic radius because once electrons are lost, the
nucleus pulls in on the remaining electrons, resulting in a smaller electron cloud.
Elements with increased ionic radius: P3-
O2- C4- Br-
Anions (negatively charged ions) have an increased atomic radius because the acquisition of electrons
allows the electron cloud to grow in size due to the like charges repelling each other and the nucleus not
being able to exert as much force on the greater number of negative charges.
Be sure to look over the notes from class and be familiar with features from
each periodic trend. You will be providing answers in complete sentences, so
make sure you can justify each response, as this will be the majority of points
for the quiz.