Final answer:
A poison is a substance that can cause harm or death when a person is exposed to a sufficient quantity. The impact of a poison is dose-dependent, meaning the more you are exposed to, the greater the potential for harm. Common poisons include household chemicals, heavy metals, and metabolic poisons like carbon monoxide and cyanide.
Step-by-step explanation:
A substance that can cause illness or death when absorbed or ingested is generally referred to as a poison. The severity of the poisoning depends on the dose—or the amount—of the substance, which is why the principle 'the dose makes the poison' is often quoted. Moreover, specific substances such as arsenic and mercury that are toxic even in small quantities have historically been known as poisons.
There are also household chemicals that are highly reactive and thus very dangerous upon ingestion or skin contact; they can be corrosive poisons. Other substances, like carbon monoxide and cyanide, are known as metabolic poisons because they interfere with the normal functions of the body. Exposure to heavy metals such as lead, mercury, and cadmium can cause significant health issues, as they can damage the nervous system and other organs.