Venus's atmosphere is primarily composed of carbon dioxide (CO2), which makes up about 96.5% of its atmosphere.

Here's a breakdown of the major components:

* Carbon Dioxide (CO2): 96.5%

* Nitrogen (N2): 3.5%

* Other gases: Trace amounts of sulfur dioxide, argon, water vapor, and other gases.

It's important to note that Venus's atmosphere is incredibly dense and thick, about 90 times denser than Earth's atmosphere. This thick atmosphere traps heat, creating a runaway greenhouse effect that makes Venus the hottest planet in our solar system.