In an experiment, a 25.0-g sample of mercury is reacted with 5.0 g of oxygen. At the end of the reaction 6.2 g of mercury and 3.5 g of oxygen were found unreacted. According to the law of conservation of mass, how many grams of mercury oxide are formed? (Assume mercury oxide in the only product in this reaction.) show your answer

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.