During which Civil War battle was Jackson accidentally shot?
A. Chancellorsville
B. Battle of Spotsylvania
C. Battle of Chickamauga

Answer is 456 mmHg.

Explanation;

This is a simple unit conversion problem.

1 atm = 760 mmHg

Hence,

0.600 atm = (760 mmHg / 1 atm) x 0.600 atm

                 = 456 mmHg

Pressure can be measured by using many units such as atm, Pa, torr, bar, cmHg, mmHg and so on.

The relationships among those units as follows

1 atm = 101325 Pa = 1.01325 bar = 760 torr, 760 mmHg = 76 cmHg