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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B- 90 grams bc 45 mL times 2 equals 90
Answer: (C) Although the average kinetic energy of the colliding substances increases, this has no influence on activation energy.
Explanation:
After increasing the temperature of the reaction , the rate of the chemical reaction increases due to increase in the average kinetic energy of the particles. At increased temperature high proportions of particles can react making the reaction faster.