Answer:
The ratio of electric force to the gravitational force is 
Explanation:
It is given that,
Distance between electron and proton, 
Electric force is given by :

Gravitational force is given by :

Where
is mass of electron, 
is mass of proton, 
is charge on electron, 
is charge on proton, 



So, the ratio of electric force to the gravitational force is
. Hence, this is the required solution.
Answer: Plant A
Explanation: The control group is participants who do not receive the experimental treatment.
The Asthenosphere is where the convection currents in the Earth occor
Answer: C solar energy
Solar energy has the greatest impact on primary productivity.
Explanation:
Primary productivity is the amount of organic compounds synthesized from carbon dioxide. Primary production occurs by the process of photosynthesis. Since the process of photosynthesis uses sunlight as the energy source solar energy has the greatest impact on primary productivity.
The synthesis can occur in atmosphere as well as aquatic environment. The organisms that perform the function of primary production are called producers .In terrestrial regions plants are the producers and in aquatic systems algae are the primary producers.
As we know that acceleration is directly proportional to force, therefore as the force is doubled, acceleration gets doubled too.