This problem involves Newton's universal law of gravitation and the equation to follow would be.
F = GM₁M₂/r²
Given: M₁ = 0.890 Kg; M₂ = 0.890 Kg; F = 8.06 x 10⁻¹¹ N; G = 6.673 X 10⁻¹¹ N m²/Kg²
Solving for distance r = ?
r = √GM₁M₂/F
r = √(6.673 x 10⁻¹¹ N m₂/Kg²)(0.890 Kg)(0.890 Kg)/ 8.06 x 10⁻¹¹ N
r = 0.81 m
If one of two interacting charges is doubled, the force between the charges will double.
Explanation:
The force between two charges is given by Coulomb's law

K=constant= 9 x 10⁹ N m²/C²
q1= charge on first particle
q2= charge on second particle
r= distance between the two charges
Now if the first charge is doubled,
we get 
F'= 2 F
Thus the force gets doubled.
Compounds. two or more compounds.
1. a=Δv/Δt=(v-vo)/t=(0-25)/5=-25/5=-5 m/s²
The "-" sign shows us that the car has a slow motion
2.a=Δv/Δt=(v-vo)/t=(10-0)/4=10/4=2,5 m/s²
3.they do not have acceleration because they go at constant speed
Ok, condensation is part of the water cycle. Acid rain comes from acidic air pollution. Burning fossil fuels is a green house gas that contributes global warming. I'd have to go with B.