El tiempo que transcurre para que los moléculas de reactivos rompan sus enlaces y elaboren nuevos enlaces para dar origen a los productos, se conoce como

The time that elapses for the reactant molecules to break their bonds and make new bonds to give rise to the products is known as

Reaction rates

Explanation:

Reaction rates is time that elapses for the reactant molecules to break their bonds and make new bonds to give rise to the products.

Reaction rate is the speed at which chemical reactions occur. It is the change in concentration of a reactant or product per unit time. The rate of reaction changes with time significantly. Reaction rate is measured based on the rate of disappearance of a reactant or appearance of a product with increasing reaction time.  

1. and 2. question: in which equation? or i don't understand you, 3. a), 4. c), 5. c), 6. b), 7. d), 8. d) if small number is underlined(behind symbol) , b) if big number is underlined(in front of symbol)9. what is underlined there? 10. c)

Both models are effective because they show the valence electrons, and these valence electrons indicate the reactivity of an element.