Answer:
solid
Explanation:
Melting and boiling points of Group 7 elements State at room temperature Room temperature is usually taken as being 25°C. At this temperature, fluorine and chlorine are gases, bromine is a liquid, and iodine and astatine are solids. There is therefore a trend in state from gas to liquid to solid as you go down the group.
the number of protons and the number of neutrons determine an element's mass number. :D
To find the neutrons you add the mass number and the atomic number for neutrons
Hope this helps
-Zayn Malik