4. Which of the following scenarios is impossible? A mixture of iron and cobalt fully adheres to a magnet. The positive pole of a coin adhered to the positive pole of a magnet. I broke a magnet and got two new pieces each with a positive and negative pole. A paramagnetic object underwent a stimulation and now all its particles point to the same side

The correct answer is: The positive pole of a coin adhered to the positive pole of a magnet.<br /><br />Explanation: Magnets have two poles, a north pole and a south pole. Opposite poles attract each other, while like poles repel each other. Therefore, it is impossible for the positive pole of a coin (which can be considered as having a north pole) to adhere to the positive pole of a magnet (which is also a north pole). The other scenarios are possible: a mixture of iron and cobalt can adhere to a magnet, breaking a magnet results in two new pieces each with a positive and negative pole, and a paramagnetic object can undergo stimulation and have its particles point to the same side.