HS-PS1-5

Apply scientific principles and evidence to provide an explanation about the effects of changing the temperature or concentration of the reacting particles on the rate at which a reaction occurs.

  1. Chemistry

    Scientists Say: Catalyst

    Sometimes a chemical reaction can take a while. If speed is needed, a catalyst can help.

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  2. Environment

    Trees can make summer ozone levels much worse

    The greenery can release chemicals into the air that react with combustion pollutants to make ozone. And trees release more of those chemicals where it gets really hot, a new study finds.

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  3. Earth

    Ancient Arctic ‘gas’ melt triggered enormous seafloor explosions

    Methane explosions 12,000 years ago left huge craters in bedrock on the Arctic seafloor. Scientists worry more could be on the way today as Earth’s ice sheets melt.

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  4. Planets

    How Earth got its moon

    How did our moon form? Scientists are still debating the answer. It may be the result of some one big impact with Earth — or perhaps many small ones.

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  5. Chemistry

    Here’s how hot water might freeze faster than cold

    There’s a new explanation for how hot water freezes faster than cold water. But not everyone agrees it’s right, or that the effect can happen at all.

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  6. Physics

    Sunlight + gold = steaming water (no boiling needed)

    Nano-gold is the new black, at least when it comes to absorbing heat. When tiny gold particles get together, they become energy super-absorbers — turning them black.

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  7. Earth

    Carbon dioxide could explain how geysers spout

    A new study overturns 150 years of thinking about Yellowstone’s geysers. Carbon dioxide, not just hot water, may be driving those spectacular eruptions.

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  8. Tech

    Cool Jobs: Big future for super small science

    Scientists using nanotechnology grow super-small but very useful tubes with walls no more than a few carbon atoms thick. Find out why as we meet three scientists behind this huge new movement in nanoscience.

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  9. Physics

    News Brief: Brrrrr — that’s really cold!

    These atoms approached — and got oh so very close — to absolute zero.

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  10. Cookie Science 13: The deal with gluten

    To find out how to improve my gluten-free cookies, I learned a lot about what gluten does, and what other baking ingredients might take its place.

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  11. Physics

    Very-sub-zero water

    Using lasers, scientists measured the temperature of water droplets that remained liquid even when super-cold.

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  12. Physics

    World’s coolest ‘clock’ is also crazy-accurate

    This is the time to beat — the world’s most accurate atomic clock ever. At its heart is a ‘fountain’ of cesium atoms chilled nearly to absolute zero!

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