How much energy is required to vaporize 1.5 kg of copper? (Refer to table of latent heat values.)

A. 2580 kJ
B. 7095 kJ
C. 3153 kJ
D. 311 kJ

4d^55s^1 ( third choice)

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.