A. both permanent magnets and electromagnets.
Explanation:
A permanent magnet can affect and attract any other permanent magnet and even electromagnet.
They also affect any magnetic materials especially metals that can be magnetized.
In the vicinity of such substances, an attractive or repulsive force sets in and they both interact in the presence of the force field in place.
Permanent magnets cannot magnetize non-magnets.
An electromagnet is a magnet produced by the passage of electric current through a wire wound round a metallic core.
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Electromagnet brainly.com/question/2191993
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Answer:
A lot of them.
Explanation:
It would take hundreds of thousands of trees to clear all of the emmisions.
The solution changed color because the substances are not neutral.
<h3>
pH</h3>
Chemical substances have different concentrations of the hydrogen cation, called PH.
The higher the pH, the more basic the substance, and the lower the more acidic.
Bromothymol blue is a pH indicator that changes its color according to the pH of the substance, yellow for acid, blue for basic and green for neutral.
In the case of the reactions in question, we have the release of CO2 (acid) in combustion and in cellular respiration, changing the color of bromothymol blue to yellow.
Learn more about pH in: brainly.com/question/491373
