I need help plz with number 5

the number of protons in the nucleus of a given element. has slight luster and conducts electricity at high temperatures like metal.but like a nonmetal,boron is brittle and does not conduct electricity well at low temperatures. in graphite, carbon is a soft,brittle solid.it is reflective,ductile,or malleable.

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.

it should have an internal chamber and two thermometers sticking out of the top. the internal chamber will also be closed off from the outside.