An unknown metal is very reactive; it reacts violently with water and must be stored in a moisture-free environment. it is solid at room temperature. which group does the metal likely belong to?

            This Metal belongs to Group I (Alkali Metals).

                    Alkali Metals present in Group I are considered as the most reactive metals in periodic table. There reactivity increases tremendously down the group. The reactivity is mainly due to less ionization energies. Therefore, going from top to bottom along the group the ionization energies decreases hence, increasing there reactivity respectively.

                   Alkali metals when reacted with water undergoes an exothermic reaction resulting the formation of corresponding metal hydroxide and hydrogen gas i.e.

                                     2 M  +  2 H₂O    →     2 MOH  +   H₂

                   Also, these metals are in solid state at room temperature (i.e. 25 °C) and their boiling points are as follow,

                                                Lithium  =  180.5 °C

                                                Sodium  =  97.79 °C

                                                Potassium  =  63.5 °C

                                                Rubidium  =  39.48 °C

                                                Cesium  =  28.44 °C

answer: mercury

explanation: