Venus, The hottest Planet.

 Venus is the hottest planet in the solar system because Venus has thick blanket of atmosphere which allows sun rays to enter but doesn't let terrestrial radiation to reflect back in which the trapped heat makes the planet hot. 

                                          Figure 1.1 Venus 

                                       Figure 1.2 The Heat Budget of Earth.

The above figure 1.2 the heat budget of the earth shows that once sun rays falls on the earth surface, it tend to reflect back the terrestrial radiation. and due to the presence of the atmosphere layer, some amount are retained in the atmosphere. Like wise, Venus planet is said to have atmosphere which is thicker than the one that earth has, thus, it traps all the incoming radiation and do not let the terrestrial radiation to reflect back, meaning the heat is retained inside by the thick atmosphere. Therefore, Venus is the Hottest planet of the solar system.