Question

Planet A is an inner planet with no moon and hardly any atmosphere. Planet B is an inner planet with no moon but with a dense atmosphere. Which pair of planets is being described?

Answer 1

Hey friend!
You stuck? 

There are two inner planets that have no moon. Mercury, and Venus. Only Mercury has hardly any atmosphere. Therefore, Planet A is Mercury. Venus which is composed primarily of carbon dioxide with a small amount of nitrogen is considered a planet with a dense atmosphere. Therefore, Planet B is Venus. 

Hope this helps! {Don't forget Brainliest!} :)

Answer 2

Answer: Planet A: Mercury.

Planet B: Venus.

Explanation: In our solar system there are only two planets without moons or natural satellites:

Mercury and Venus.

While Mercury has a very tenuous and variable atmosphere, Venus atmosphere is so dense that is almost impossible to see the surface of the planet, big clusters of clouds travel in the skies of Venus at really big speeds, reaching numbers like 350 km/h

So Mercury is the inner planet with no moon and almost no atmosphere, this means that Mercury is planet A, and Venus is the planet with no moon and a dense atmosphere, so Venus is planet B.