The temperature of a typical laboratory freezer unit is −20 oC. If liquid water in a completely- filled, closed container is placed in the freezer, estimate the maximum pressure developed in the container at equilibrium. The enthalpy of fusion of water may be taken as 333.4 kJ kg-1, independent of temperature and pressure, and the densities of ice and liquid water at −20 oC are 0.9172 and 1.00 g cm-3, respectively.

< > according to newton's third law of motion, forces always act in equal but opposite pairs. another way of saying this is for every action, there is an equal but opposite reaction.< >

i think it's letter a.

the seeing the electronic configuration we can say that the element is fluorine.

fluorine is the most electronegative element in the periodic table.

but by only seeing the configuration we cannot say about its reactivity because we don't know if its configuration after excitation or by addition of electrons.

but if not then, it is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions. as the most electronegative element, it is extremely reactive: almost all other elements, including some noble gases, form compounds with fluorine.