Deutsch: Wasserstoff / Español: Hidrógeno / Português: Hidrogênio / Français: Hydrogène / Italiano: Idrogeno
Hydrogen is a chemical element with chemical symbol H and atomic number 1. With an atomic weight of 1.00794 u, hydrogen is the lightest element on the periodic table. Its monatomic form (H) is the most abundant chemical substance in the universe, constituting roughly 75% of all baryonic mass.

In the environment context, hydrogen is an element that can have both positive and negative impacts on the environment depending on how it is produced and used. Here are some examples of hydrogen in the environment context:

1. Renewable energy: Hydrogen can be produced from renewable energy sources such as wind and solar power through a process called electrolysis. This renewable hydrogen can then be used as a clean fuel for transportation or to generate electricity without emitting greenhouse gases.

2. Fuel cells: Hydrogen fuel cells are a technology that generates electricity by combining hydrogen and oxygen without combustion, producing only water as a byproduct. Fuel cells can be used in a variety of applications such as powering vehicles, buildings, and portable electronics.

3. Fossil fuel production: Hydrogen is also used in the production of fossil fuels, such as refining oil and gas. However, this process often produces greenhouse gases as a byproduct, contributing to climate change.

4. Chemical manufacturing: Hydrogen is used in many chemical manufacturing processes, including the production of fertilizers and plastics. However, these processes can also have negative environmental impacts, such as air and water pollution.

Some similar things to hydrogen in the environment context might include:

1. Carbon: Carbon is an element that has a significant impact on the environment. It is a major component of greenhouse gases and plays a key role in climate change. However, carbon can also be captured and stored underground through a process called carbon capture and storage (CCS).

2. Nitrogen: Nitrogen is an essential element for life, but excessive nitrogen from fertilizers and other sources can lead to environmental problems such as eutrophication, where excessive nutrients cause algal blooms.

3. Methane: Methane is a greenhouse gas that is produced by natural processes such as decomposition and by human activities such as livestock farming and fossil fuel extraction. It is also a potential energy source and can be used in fuel cells or as a fuel for vehicles.

4. Biofuels: Biofuels are fuels produced from renewable sources such as crops and algae. They can be used as a clean energy source for transportation and power generation.

5. Carbon capture and storage: Carbon capture and storage (CCS) technologies are used to capture carbon dioxide emissions from industrial processes and store them underground. This can help to reduce greenhouse gas emissions and mitigate the impacts of climate change.

6. Renewable energy sources: Renewable energy sources such as solar, wind, and geothermal power are sources of clean energy that can be used to reduce greenhouse gas emissions and address climate change.