At room temperature, hydrogen exists as a gas. This is because the temperature is typically above the boiling point of hydrogen, which is -252.87°C (-423.17°F). In its gaseous state, hydrogen molecules are widely spaced and move freely, allowing it to fill any container it is in.
Hydrogen is the simplest and lightest element, consisting of just one proton and one electron. Due to its low molecular weight and the weak interatomic forces present in hydrogen gas, it remains in a gaseous form under standard temperature and pressure conditions. If we were to cool hydrogen to below its boiling point, it would transition into a liquid state, and further cooling would result in solid hydrogen. However, these states are only observed at much lower temperatures than those typical in everyday environments.