chemistry

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A scientist is performing an experiment on a
powder. Which of the following is a sign that a chemical change has definitely occurred during his experiment?

The powder catches on fire.

The powder releases bubbles.

The powder heats up.

The powder breaks apart into smaller particles.

  • chemistry -

    a yes
    b yes
    c either
    d no

    c can be either. If it heats up because you built a fire under it that is a physical change. If it heats up because of the experiment being conducted it is a chemical change.

  • chemistry -

    The answer is A :D

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