Which factor distinguishes a metallic bond from an ionic bond or a covalent bond?
a. the mobility of protons
b. the equal sharing of electrons
c. the unequal sharing of electrons
d. the mobility of electrons

d. the mobility of electrons

Explanation:

Covalent bond is the bond which is formed with the sharing of the electrons between the two atoms which are taking place in the bond. It is generally formed between the atoms with similar electronegativity values.

Metallic bond is the bond which is formed by electrostatic attraction force between the positively charged metal ions and the conduction electrons.

Thus, in metallic bond, there is a formation of conduction band and the valence band where the electrons have mobility and have transitions in between them but in covalent bonding, the electrons are shared in the bond and are not mobile.

answer : one can design an experiment using a liquid and an additive that can be added to the liquid and observe the chemical changes in the reaction species.

one would need a beaker which is filled with a known amount of the liquid in which thermometer is placed to measure the temperature changes; after addition of the additive to the liquid solution one can note down the temperature change and find whether the reaction is endothermic or exothermic in nature. by subtracting the initial temperature value with the final temperature one can find the temperature changes.

various combinations of liquid and additive can be used. liquid in this case can be a known quantity of water and additives can be epsom salt or without epsom salt the experiment can be conducted to notice the changes. water and ice, hydrogen peroxide and dry yeast, vinegar and baking soda,etc.