Answer:
Convection?
Explanation:
The circulation of heat currents?
Zn and HCl are the reactant in the equation above. zinc react with 2 moles of Hcl to form zinc chloride and a hydrogen molecule. The one equation means that the reaction proceed to the forward side only therefore no reverse of the reaction.
Answer:As the tetrapod evolved, the number of digits decreased
Explanation:
The answer is theory because it says if and that means theory