To convert 560 millimeters of mercury (mmHg) to atmospheres (atm), you can use the conversion factor: 1 atmosphere (atm) is equal to 760 mmHg.

The conversion formula is:

Pressure in atmospheres (atm) = Pressure in millimeters of mercury (mmHg) / 760

For your specific example:

Pressure in atmospheres = 560 mmHg / 760

Calculating this:

Pressure in atmospheres is approximately 0.737 atm
So, 560 mmHg is approximately equal to 0.737 atmospheres.

Essentially, we multiply the mmHg given by the conversion factor 1 atm/760 mmHg. The units mmHg cancel out, leaving atm, which is what we are trying to find.

It's important to note that atmospheric pressure varies with altitude. As you move to higher elevations, atmospheric pressure decreases. Therefore, the conversion factor may not be accurate at locations significantly above or below sea level.