Asphere of 200 mm diameter made of cast iron initially at uniform temperature of 400 °c is quenched into oil. the oil bath temperature of 40 °c. if the temperature of the sphere is 100 °c after 5 minutes, find the heat transfer coefficient on the surface of the sphere. take cp (cast ron) 0.32 kj/kg °c, p neglect internal thermal resistance [ans. 134 kw/m2 °c] 3 (cast ron) -7000 kg/m

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.