International (IUPAC) values are: 0 oC and 10e5 Pa.
Only in USA the values are 20 oC and 1 atm.
Sometimes other values are used.
273 K (0° Celsius) and 1 ATM pressure
The accepted standard state values for temperature is 298 K (25°C) and pressure is 1 bar (100 kPa).
That is the element potassium at STANDARD TEMPERATURE AND PRESSURE. Standard temperature is 273 K and standard pressure is 1 atm.
Standard temperature and pressure (STP) is defined as a temperature of 0 degrees Celsius and a pressure of 1 atmosphere (atm).
To figure out SATP (standard ambient temperature and pressure), you can refer to common values: 25 degrees Celsius (298.15 K) and 1 atm (101.3 kPa). These values are important for measuring gases at standard conditions.
For chemistry, after IUPAC rules the standard temperature is 0 oC and the standard pressure is1 bar.
At STP(Standard Temperature and pressure), the temperature is zero degrees Celsius(273 Kelvin) and the pressure is 1 atmosphere. At RTP(Room temperature and pressure), the temperature is 25 degrees Celsius(298 Kelvin) and the pressure is 1 atmosphere.
The saturation temperature of water at standard atmospheric pressure is 100 degrees Celsius.
If the water is pure, and the temperature and pressure are both at standard values,then the mass of one milliliter of water is 1 gram.
Normal temperature pressure refers to conditions at 0°C (273K) and 1 atm pressure, while standard temperature pressure refers to conditions at 25°C (298K) and 1 atm pressure. These conditions are used as reference points for certain calculations and measurements in chemistry and physics. The main difference is the temperature at which they are defined, with standard temperature pressure being at a slightly higher temperature than normal temperature pressure.
Usually we use a temperature of 20 °C and an absolute pressure of 101.325 kPa for 1 atmosphere.
STP in physics and chemistry stands for standard temperature and pressure.