# At 0m (sea level) what is the atmospheric pressure?

By definition it's $1 \cdot \text{atmosphere}$......
Most chemists would use atmospheres to measure pressure, as it is quite an intuitive unit. $\text{1 atmosphere}$ of pressure will also support a column of mercury that is $760 \cdot m m$ high; and this is a VERY convenient unit for high vacuums and small pressure differences (convenient until you break the mercury manometer and get mercury all over the lab!).
In kilopascals, $1 \cdot a t m \equiv 101.3 \cdot k P a$, where $1 \cdot \text{Pascal"-=1*"Newton} \cdot {m}^{-} 2$, a force per unit area, a pressure as required.