Name the physical quantity which is expressed in the unit .atm.. State its value in pascal.

Explanation

To solve the question, we need to follow these steps:

### Step 1: Identify the Physical Quantity
The physical quantity expressed in the unit "atm" (atmosphere) is **pressure**.

### Step 2: Understand the Value of 1 Atmosphere
At normal temperature and pressure (NTP), 1 atmosphere is defined based on the height of a mercury column. Specifically, 1 atmosphere is equivalent to the pressure exerted by a 0.76 meter column of mercury at sea level.

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