The given chemical reaction is between calcium carbonate and hydrochloric acid to produce calcium chloride, carbon dioxide and water. This reaction can be represented as,

When the concentration of the reactants is increased, the number of collisions that take place between the reactant molecules increases. This speeds up the reaction. Therefore, when the concentration of HCl is doubled as long as there is enough calcium carbonate to react with HCl, the number of effective collisions giving products increases, this causes the rate of forward reaction to increase.
The temperature or the average kinetic energy of the molecules
The electron is the only subatomic particle that has a negative charge
Answer:
619.465 kilometers
Explanation:
1609 m = 1 mile
so 385 miles is equal to 619465 meters (385 x 1609= 619465)
1000 meters = 1 km
so 619465 meters is 619.465 kilometers