Final answer:
Standard Temperature and Pressure (STP) refers to 0°C (273.15 K) and 1 atm pressure for a gas. Therefore, the correct answer is: 4) 1 atm and 0° C
Step-by-step explanation:
The conditions meant by STP are: 1) A temperature of 0 degrees Celsius 2) A pressure of 1 atmosphere Temperature and pressure are both specified because both these variables can have a significant impact on the behavior of gases, which is often what STP is used to refer to.
Let's break down the definition and compare it to the provided options:
1) 0 degrees Celsius is equal to 273.15 Kelvin. It's important to note that temperature in scientific contexts is often given in Kelvin, but here 0 degrees Celsius is the correct STP reference temperature, which translates to 273.15 Kelvin.
2) 1 atmosphere is a unit of pressure commonly used to represent the average atmospheric pressure at sea level on Earth.
Now let's evaluate the given options: 1) 0 atm and 1° C - This cannot be STP because a pressure of 0 atmospheres does not reflect a standard condition; it represents a total vacuum. 2) 1 atm and 0 K - 0 Kelvin is absolute zero, which is not the standard temperature for STP.
3) 0 atm and 273 K - Again, this includes 0 atmospheres, which means a vacuum and is not the pressure condition for STP. 4) 1 atm and 0° C - This option lists the correct pressure and temperature for STP, which are 1 atmosphere and 0 degrees Celsius respectively.
Therefore, the correct answer is: 4) 1 atm and 0° C Standard Temperature and Pressure (STP) refers to the conditions of 0°C (273.15 K) and 1 atm pressure for a gas.