60,000-year-old poison arrowheads show early humans’ hunting tactics

abstraction: An idea or concept, as opposed to a concrete example.

chemical: A substance formed from two or more atoms that unite (bond) in a fixed proportion and structure. For example, water is a chemical made when two hydrogen atoms bond to one oxygen atom. Its chemical formula is H₂O. Chemical also can be an adjective to describe properties of materials that are the result of various reactions between different compounds.

clay: Fine-grained particles of soil that stick together and can be molded when wet. When fired under intense heat, clay can become hard and brittle. That’s why it’s used to fashion pottery and bricks.

particle: A minute amount of something.

prehistoric: An adjective for something that happened tens of thousands to millions of years ago, periods before people began deliberately recording events.

prey: (n.) An organism hunted by another, often for food. (v.) To attack and eat another organism.

quartz: A type of mineral made from silicon dioxide. The most common mineral on Earth, it can occur in any rock type: igneous, metamorphic or sedimentary.

sediment: Material (such as stones and sand) deposited by water, wind or glaciers.

sophisticated: A term for something that is advanced, complex and/or elegant.

spectrometry: An instrument that measures a spectrum, such as light, energy, or atomic mass. Typically, chemists use these instruments to measure and report the wavelengths of light that it observes. The collection of data using this instrument (a process is known as spectrometry) can help identify the elements or molecules present in an unknown sample.

strategy: A thoughtful and clever plan for achieving some difficult or challenging goal.

toxic: Poisonous or able to harm or kill cells, tissues or whole organisms. The measure of risk posed by such a poison is its toxicity.