In which atmosphere layer does 80 percent of the gas in the atmosphere
reside?

The correct answer is Troposphere.

Explanation:

The troposphere is the closest atmospheric layer of the earth's surface and 80% of the total mass of the atmosphere and 99% of the water vapor are located here.

In this layer, the higher the altitude, the temperature and the steam will be lower. This steam is responsible for regulating air temperatures thanks to the absorption of energy from the sun. Here is the air we breathe and all the climatic processes of our planet.

80% of the mass of the atmosphere is located in this layer because in it the air is much denser than in the other layers.

see the picture for the vector

the magnitude of the vector by pythagorean theorem

r = √( (-10)^2 + (3)^2 ) = √109

magnitude = √109 units

the direction angle between vector and x-axis is

tan^(-1)(3/10) = 16.699

so the direction is approximately 16.7 degrees north of west