All of the answer choices are correct because they accurately state a fact about magnetic materials. Iron and steel are both magnetic materials and would be attracted to a strong magnet. Plastic, aluminum cans, and cotton are all materials that would not be attracted to a magnet.

The iron pipe will be strongly attracted to the magnet because it has magnetic properties. Iron is a magnetic metal, so it would be drawn and stick to the magnet. Copper, plastic, and wood are not magnetic and would not be attracted to the magnet.

Steel objects will be strongly attracted to the junkyard magnet, whereas aluminum, wood, and plastic will not. The magnet will only attract objects with magnetic properties, and of this list, steel is the only object that it would pick up. Steel can be very heavy, and humans cannot easily pick up a large piece by themselves.

The best use for magnets to solve a problem would be securing a broken freezer door. If a magnet is attached to both sides (the door the frame of the freezer) with the opposite sides facing each other, they will be attracted and stick together. Magnets would not keep a dog out of a garden, would not work as a lightbulb, and magnets will not be attracted to a wooden table.

Brad and Brian can use their scientific knowledge of magnets to determine which objects can be removed from the mixture. The items that can be removed have the quality of being magnetic. Bran and Brian can remove the iron filings and paperclips from the mix because they are both metal and magnetic. The other objects are made of materials that would not be attracted to the magnet.

This problem can be solved, but it is tricky! Not touching the car is the hardest part because everyone is used to steering them with their hands. Drew could use a magnet to solve this problem because magnets do not need to touch to attract other magnetic items. He could hold the magnet above the car and steer it through the maze.

These are all items that hikers use, and they solve problems for them while they are out in the woods. The only thing that relies on magnets though, is the compass. A water bottle, hiking boots, and a map are all helpful but do not rely on magnets. A compass works because the magnet responds to Earth's magnetic field. Earth is like a giant magnet that creates a magnetic field. The north end of a compass is drawn to align with Earth's magnetic North Pole. While the hikers move through the woods, the compass' needle moves towards the North end of to help them find their way.

Magnets seem like they might only be suitable for holding the grocery list on the refrigerator, but they have many uses and can solve simple problems dealing with movement. Magnets can attract/pull and repel/push other magnetic objects creating movement. If something needs to be moved and it has a magnetic quality using a magnet is a simple way to complete the task.

This solution works because the metal is magnetic, so a magnet will be attracted to it and stick to it. The paper is light, so a strong magnet is not needed. If the door were made of a material that does not have a magnetic quality, the magnet would not work, and an alternate solution would be required.

Mrs. Harley had a good idea to use a magnet to hold the sign up because the metal door has magnetic properties, but the sign is too heavy for the size magnet she selected. Mrs. Harley will need to choose a larger or stronger magnet to hold up the weight of the sign. Wood can be dense and heavy, so it is dragging the magnet down and falling off the door. A stronger magnet will solve this problem.