The noun 化合物 (huàhéwù) means "compound" in the chemical sense — a substance formed from two or more elements chemically bonded together. It is a scientific term used in chemistry and related fields. For example, 这一化合物存在于小行星上 means "this compound exists on an asteroid."
水是最常见的化合物之一。
Shuǐ shì zuì chángjiàn de huàhéwù zhī yī.
Water is one of the most common compounds.
科学家在实验室中合成了一种新的化合物。
Kēxuéjiā zài shíyànshì zhōng héchéng le yì zhǒng xīn de huàhéwù.
Scientists synthesized a new compound in the laboratory.
这种化合物对环境没有危害。
Zhè zhǒng huàhéwù duì huánjìng méiyǒu wēihài.
This compound poses no harm to the environment.