Question

The halogen which is solid at room temperature is:
(A)${I_2}$
(B)$B{r_2}$
(C)$C{l_2}$
(D)${F_2}$

Answer 1

Hint: Halogens are nonmetallic elements which are highly reactive. They belong to group seventeen in the modern periodic table. All the halogens have seven valence electrons, so they are highly reactive. This reactivity decreases as we go from top to bottom in the group.

Complete answer:The halogen group has elements that occur in three different states of matter at room temperature. Fluorine and chlorine are gases, bromine is a liquid and iodine and astatine are solids. This group is quite diverse and the halogens also vary in their colors. Fluorine and chlorine are green in color, bromine is red and astatine and iodine are nearly black in color. Iodine is solid at room temperature as we can obtain it in crystal form in some experiments.
Therefore, option A is the correct answer.

Additional information: Halogens are the most electronegative elements of each period of the modern periodic table. The size of halogens increases as we go from top to bottom of the group because the number of electrons and number of shells increases.

Note:
As the atomic mass increases down the group, the physical state of the bottom elements is solid at room temperature. Due to low molecular mass, the elements present at the top are in gaseous state at room temperature. As bromine is in the middle of the group and also its atomic mass is not too large to be a solid and also not low to be a gas. So, the physical state of the element bromine is liquid at room temperature.