Select all that apply to the property of hardness.

hardness is a physical property
hardness is indicative of the strength of chemical bonds between elements.
hardness is determined through a complicated process that requires expensive instruments.
friedrich mohs developed the standard hardness scale.
diamond can scratch quartz.

3 1/4 %

explanation:

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.