Which of the following statements is/are true of the Group 1A elements of the periodic table?
1) Lithium, sodium, potassium, rubidium, cesium, and francium are the most reactive of the metals.
2) Hydrogen behaves as a nonmetal because the electron in its small 1s orbital is bound very tightly to the nucleus.
3) The first ionization energy of the elements decreases and the atomic radius increases as one moves down the group.
A) 1 only
B) 2 only
C) 3 only
D) 1, 2, and 3
E) 1 and 2

Question

Which of the following statements is/are true of the Group 1A elements of the periodic table?
1) Lithium, sodium, potassium, rubidium, cesium, and francium are the most reactive of the metals.
2) Hydrogen behaves as a nonmetal because the electron in its small 1s orbital is bound very tightly to the nucleus.
3) The first ionization energy of the elements decreases and the atomic radius increases as one moves down the group.
A) ​1 only
B) ​2 only
C) ​3 only
D) ​1, 2, and 3
E) ​1 and 2

Quizplus · Accepted Answer

1) This statement is true. Group 1A elements are the most reactive metals because they have only one valence electron and are able to easily lose it to form a +1 ion.
2) This statement is partially true but not specific to Group 1A elements. Hydrogen may behave as a nonmetal due to the high electronegativity of its single valence electron or as a metal in certain circumstances.
3) This statement is true. As one moves down Group 1A, the first ionization energy (energy required to remove the outermost electron) decreases because the valence electron is further from the nucleus and less tightly bound. The atomic radius also increases due to the additional electron shell.

Which of the Following Statements Is/are True of the Group