Scientific name: Mg
Magnesium is a highly reactive metal that is not found in its pure form. It is quite common, and is essential for life. The pure metal burns bright white and is an ingredient in flares.
A magnet is material that produces a magnetic field. Because of this field, magnets can both attract and repel each other (depending on which end of the magnet you use) and can attract ferromagnetic materials, such as iron. The small pieces of iron filing on the magnet in the picture follow the shape of the magnet's magnetic field. Magnets are most often seen stuck to refrigerators.
A magnifying glass is a glass lens mounted in a frame with a handle. When you look through a magnifying glass at something, it appears much bigger. You use magnifying glasses to see details on things you couldn't normally see.
Magpies are a black and white bird related to the crow. They are very intelligent. They eat dead animals they find, insects and anything else they find that they can eat. The magpie in the picture is an Australian magpie.
Mahogany is a generic name given to several different kinds of reddish-brown furniture grade timber, either from tropical regions or the Americas.
Scientific name: adiantum aethiopicum
Maidenhair ferns are a popular houseplant. They have very distinctive fronds that don't look at all like 'traditional' fern fronds. The fronds look more like leaves, but they still start tightly curled up like other ferns. Like most ferns they like damp, shady places.
Mail is letters and parcels that are sent through the postal system. They are delivered to your letterbox by a postman.
Main means the largest or most important of something. For example a company might have their main office, and many towns have a main street.
Maine coons are one of the largest cat breeds. They are from the United States, where it is thought they might have come about from local cats breeding with bobcats. They are gentle cats, with long, flowing hair and sometimes tufts on the ends of their ears.
You maintain something when you keep it in its current state. For example, you might maintain a friendship with someone, or maintain your house to keep it in good condition. This is called carrying out maintenance. The soldiers in the picture are maintaining grave sites.