About 3 Kelvin (-270 oC)
ok how would the earth be like without plate tetonics
nothing
... like Mars.
Without the atmosphere, Earth would be exposed to harmful radiation from the sun, extreme temperatures fluctuations between day and night, and no protection from meteors entering the atmosphere. Life as we know it would not be able to exist without the atmosphere providing vital components like oxygen and a stable climate.
Like a ball of grass.
The earth would look like it did when it formed
Like the moon . The Apollo astronauts would have moved from searing hot temperatures in full sun to bitingly cold when in the shadow of a large rock. It would be the same on Earth probably +250C to - 250C in one step
It would be hell on earth.
It would look dead.
we will not learn math at school.
Without life, Earth's atmosphere would lack oxygen, as it is primarily produced by photosynthetic organisms. The composition of gases would likely be primarily nitrogen and carbon dioxide, similar to the early Earth's atmosphere. There would also be fewer greenhouse gases, leading to lower temperatures on the planet.
Because we have a thick atmosphere that is warmed by the sun during the day. Plus the moon is dead, it does not have a moltern core like the earth which means still cooler temperatures.