An element’s atomic number is 80. how many protons would an atom of this element

an element's atomic number is 80 then the protons would be the same number which is 80 because the atomic number is the number of protons in atoms nucleus so 80 is your answer

The solid that require the greatest energy input to melt by mass is the option;

Covalent network

Reason for the above answer is as follows;

The elementary particles of a solid are held together by bonds that require

an input of energy to unlock, and once broken, the particles are then able

to change location within their containing vessels with less restrictions

Types of bonds

a) Soluble in water b) Low melting point, b) Conduct electricity

a) High melting point temperature b) Non conductive of electricity c) Not soluble in water

a) High melting point temperature b) The liquid state and solution

conducts electricity c) Soluble in water

a) Low melting point b) Normally in the gaseous or liquid state b) Not water soluble

Therefore, the covalent network, and the solids ionic compounds require the most energy to melt, however, the strength of the ionic bond in an ionic compound is a factor the charges present and the sizes of the atom, while

the covalent network solid, are combined to form essentially as a single

molecule and therefore require the greatest heat energy input break the bonds of the molecule down in order to melt

Learn more about the properties of the different types of bonds here;