Answer:

Explanation:
Electric field in a given region is given by equation

as we know the relation between electric field and potential difference is given as

so here we have


here we know that
and 
so we will have

so we will have

Answer:
D
Explanation:
descriptive, because scientists are writing down the observations but not making comparisons.
Answer:
Valence electrons are the electrons present in the outermost shell of an atom. You can easily determine the number of valence electrons an atom can have by looking at its Group in the periodic table.
Explanation:
It seems to go against what we see with our eyes. Plus, it contradicted official church doctrine at the time.
Answer:
20000 pounds
Explanation:
Generally 1 gallon of fuel burnt gives of 20 pounds of CO₂
Difference in the gallons of fuel burnt

The 20 mpg car burns 1000 gallons of fuel more than the 30 mpg car
The amount of CO₂ would be

The fewer pounds that the 30 mpg car would release is 20000 pounds