the density of water at 0C is 0.9999g/mL, and the density of ice at 0C is 0.9168g/ml. a) Based upon these densities, does water contract or expand when it freezes? Explain. b) Suppose you have a 250-mL container completely filled with ice (no air bubbles). What volume of liquid water will form when the ice melts? c) In (b),would wter spill out of the container once the ice melted? if so, how much water would spill out? if not, how much water could you add to the container after he ice melted?

the answer is na (sodium)

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.