Question

One student made a science model with a balloon having many spots on it. The balloon was blown up gradually as shown below.

A girl blowing up a balloon with dots on it. The dots are close together and concentrated in one area before the balloon is blown up. As the balloon expands the dots are spread further apart.

What is best demonstrated by this model?

A. galaxies move closer when the universe expands

B. density of particles in space decreases when the universe expands

C. gravitational force determines the distribution of matter in the universe

D. gravitational force on galaxies decreases when the universe expands

Answer 1

B. density of particles in space decreases when the universe expands

Step-by-step explanation:

i just fished my exam and i got it right i even got it on my notes from my dba.

Also the particles (atoms) in the balloon(planet) cant make more witch means that the density of particles in space decreases when the universe expands and that's the Big Bang Theory

Answer 2

A is wrong because galaxies do not move closer during expansion. C is wrong because it does not describe what gravity does on the distribution of matter. D is wrong because of similar reasons. So the only true answer to this question is B density of particles in space decreases when the universe expands.