Venus.
The only outer planet without a thick atmosphere is Uranus. It has a thin atmosphere composed mostly of hydrogen and helium with traces of methane.
Venus has a thick atmosphere composed mostly of carbon dioxide (CO2). This carbon dioxide is found throughout the atmosphere of the planet, with the highest concentration occurring in the lower atmosphere. It is estimated to make up about 96.5% of the atmosphere.
Venus has a thick atmosphere consisting mainly of carbon dioxide with traces of sulfuric acid.
well there are no planets like that
Venus has an atmosphere that is so thick and dense that it is always cloudy. The clouds are composed of sulfuric acid droplets that completely obscure the planet's surface from view.
Venus
Your thinking of Venus which does have a high Co2 atmosphere and sulphuric rain. Mars has very little atmosphere.
The only outer planet without a thick atmosphere is Uranus. It has a thin atmosphere composed mostly of hydrogen and helium with traces of methane.
Mars has a thin, mainly carbon dioxide atmosphere.
Uranus
Saturn has the moon Titan which has a thick hazy atmosphere.
Venus has a thick atmosphere composed mostly of carbon dioxide (CO2). This carbon dioxide is found throughout the atmosphere of the planet, with the highest concentration occurring in the lower atmosphere. It is estimated to make up about 96.5% of the atmosphere.
Hard to say, as the distance from the star will also factor in, but in general, thin atmosphere would mean no insulation, it would be cold. Mars is a classic example of a planet having a thin atmosphere. It is extremely cold on Mars and has a small amount of carbon dioxide in it's atmosphere but is not in high enough concentration to warm the planet. Mercury has no atmosphere and it is hot and cold depending on which part of the planet is facing the Sun. Venus has a very dense amosphere and it is very hot, no matter which surface is facing the Sun.
The planet Mars is the only planet known with two moons and a predominantly CO2 atmosphere.
Venus.
Jupiter
Venus.