To analyze the trends for alkali metals (Group I) and noble gases (Group VIII) on the Periodic Table, let's evaluate the statements provided:
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Alkali metals (Group I):
- Atomic Radius: Alkali metals tend to have a larger atomic radius as you move down the group due to the addition of energy levels.
- Electron Affinity: Alkali metals generally have lower (or less negative) electron affinities compared to other groups because they typically prefer to lose their one valence electron rather than gain one.
- Ionization Energy: Alkali metals exhibit low ionization energies, which decrease as you move down the group. They have less attraction to their outermost electron due to increasing distance from the nucleus.
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Noble gases (Group VIII):
- Noble gases have filled valence shells, leading to very high ionization energies and low reactivity. Their electron affinities are also generally quite low because they do not tend to gain electrons.
Now, let's evaluate each statement:
A. Alkali metals have an increased atomic radius.
- True: The atomic radius increases down the group.
B. Alkali metals have a decreased electron affinity.
- True: They have a lower (less negative) electron affinity compared to many other groups.
C. Alkali metals have a decreased ionization energy.
- True: Alkali metals have low ionization energy, which decreases as you go down the group.
D. Alkali metals have an increased electron affinity.
- False: Alkali metals do not have increased electron affinities; their electron affinity is generally low and decreases.
E. Alkali metals have an increased ionization energy.
- False: Alkali metals do not have increased ionization energies; they have low ionization energies that decrease as you move down the group.
Summary of Accurate Statements:
- A: True
- B: True
- C: True
The correct responses are A, B, and C.
1 answer