Scientists Say

A weekly word defined, in a sentence and in context. Click here to find the alphabetized list.

  1. Math

    Scientists Say: Velocity

    Velocity is more than speed. It is both speed and the direction in which an object is traveling.

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  2. Animals

    Scientists Say: Apoptosis

    When it’s time for cells to die, they need to do it carefully, so they don’t harm other cells.

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  3. Brain

    Scientists Say: Puberty

    Puberty is a time when hormones surge and people develop the ability to have children. But it’s so much more than that.

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  4. Animals

    Scientists Say: Evolution

    Evolution is how species change over time. Individuals in the group vary, and some will pass on their genes. Over time, the whole species changes.

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  5. Brain

    Scientists Say: Nucleus

    Nucleus comes from the Latin term “nuc,” meaning nut or kernel. In science there are lots of nuclei. Every one of them is the center of something.

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  6. Earth

    Scientists Say: Earthquake

    An earthquake is a sudden and sometimes violent shaking of the ground.

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  7. Brain

    Scientists Say: Narcotic

    Scientists refer to a narcotic as a drug that stops pain, but the word can be used in other ways as well.

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  8. Physics

    Scientists Say: Gravity

    Gravity is a fundamental force that attracts objects with mass to other objects with mass. It decreases with distance.

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  9. Life

    Scientists Say: Theory

    A theory is an explanation of how part of the world works. It’s one that’s been tested many times and in many ways.

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  10. Chemistry

    Scientists Say: Plastic

    Plastics are made of long polymer chains and can take on many shapes. Unfortunately, they stick around for a long time.

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  11. Animals

    Scientists Say: Amphibian

    Amphibians are ectotherms that live dual lives — they start off in water, breathing with gills, and end up breathing air with lungs.

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  12. Chemistry

    Scientists say: Chemical

    A chemical is anything made of two or more atoms bonded together in a fixed structure. Chemicals make up the world around us.

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