All group 18 elements (the noble gases) exist as monatormic gases at room temperature and standard pressure. All other elements form diatomic gases, if they exist as gas under the specified conditions.
Among the listed elements there is only one noble gas:
Argon
Nitrogen exists as a diatomic molecule (N2) at room temperature and pressure.
Nitrogen (N2) is the Group 15 element that exists as diatomic molecules at standard temperature and pressure (STP).
The element hydrogen is in the gas phase at standard temperature and pressure.
The element chlorine at standard temperature and pressure is molecular and has the formula Cl2.
A molecule made of two identical atoms is called diatomic.Five diatomic elements exist as gases at room temperature (25oC/298K) and atmospheric pressure:Hydrogen, H2Nitrogen, N2Oxygen, O2Fluorine, F2Chlorine, Cl2One diatomic element is a liquid at room temperature and atmospheric pressure:Bromine, Br2One diatomic element is a solid at room temperature and atmospheric pressure:Iodine, I2
Nitrogen exists as a diatomic molecule (N2) at room temperature and pressure.
Nitrogen (N2) is the Group 15 element that exists as diatomic molecules at standard temperature and pressure (STP).
Mercury or HG is an element that is liquid at room temperature and is not a diatomic element.
The element hydrogen is in the gas phase at standard temperature and pressure.
Under most readily achieved temperature and pressure conditions, bromine gas exists as diatomic molecules. Bromine is always an element.
Bromine (Br2) is a brown liquid poisonous diatomic molecule at room temperature.
At room temperature N (N2) is a gas. N, by itself, does not exist at room temperature and standard pressure. It exists as the diatomic gas, N2.
The element boron is a solid at standard temperature and pressure.
Atmospheric pressure is the weight of the air or the pressure exerted onto the Earth by the air. Pressure changes can lead to different weather patterns.
The element chlorine at standard temperature and pressure is molecular and has the formula Cl2.
A molecule made of two identical atoms is called diatomic.Five diatomic elements exist as gases at room temperature (25oC/298K) and atmospheric pressure:Hydrogen, H2Nitrogen, N2Oxygen, O2Fluorine, F2Chlorine, Cl2One diatomic element is a liquid at room temperature and atmospheric pressure:Bromine, Br2One diatomic element is a solid at room temperature and atmospheric pressure:Iodine, I2
Chlorine is a chemical element with the symbol Cl and atomic number 17. It exists as a diatomic gas at room temperature and pressure, and has a yellow-green color and strong odor.