The elements of group 17 can be found in the periodic table, right next to the noble gases. The number 17 gives us the number of valence electrons in the last energy level. Group 17 elements have 7 valence electrons.
We can start with two correct statements among the options. The last two are correct since to complete 8 electrons an electron is needed (7+1=8). Also, the electron configuration tells us the total electrons, for example, Fluorine has 9 electrons and its electron configuration is 1s², 2s², 2p5.
Now, these elements have enough electrons to bond with another atom of the same element. For example, chlorine is a diatomic element, in nature is found as Cl2, the same as F2.
The temperature of fusion of the elements of group 17 can vary. Some of them are gaseous at room temperature, so the statement " It will only be solid at room temperature." is not true.
Answer: It will only be a solid at room temperature. Second option