Which was the first metal used by human beings?

the first man-made element

What material were the first tools made from?Group of answer choicesStones and metal.Bones and glass.Stones and bones.Metal and wood.

Identify: We use metals in a huge variety of ways. Identify as many uses as possible.

Why does man use metals still so much today when there are other materials, especially plastics, which are available? A material is generally used because it offers the required strength, and other properties, at minimum cost. Appearance is also an important factor. The main advantage of metals is their strength and toughness. Concrete may be cheaper, it is often used in buildings, but even concrete depends on its core of steel for strength.Plastics are lighter and more corrosion-resistant, but they are not usually as strong as metals. Another problem with plastics is what to do with them after use. Metals objects can be broken down and the metals are recycled after that but plastics can only dumped or burned.Not all metals are strong, however. Copper and aluminum, for example, are both fairly weak- but if they are mixed together, the result is an alloy called aluminum bronze, which is much stronger than either pure copper or pure aluminum. Alloying is an important method of obtaining whatever special properties are required: strength, toughness, resistance to wear, magnetic properties, high electrical resistance or corrosion resistance.The properties of a metal can be further improved by use of heat treatment which changes the properties of metals and alloys. For example, hardening is used to make metals harder. Tempering makes the softer and less brittle. Annealing is carried out to make a metal soft so that it can be machined more easily. In this way metallic materials can be produced to meet every kind of engineering specification and requirement.Methods of extracting, producing and treating metals are being developed all the time to meet engineering requirements. This means that there is an enormous variety of metals and metallic materials available from which to choose.1. Which material is used so popularly nowadays? 2. What does the word “them” in paragraph 2 refer to? 3. Which material is stronger than pure copper or aluminum? 4. What process can help change the properties of metals and alloys? 5. How many methods are developed to meet engineering requirements?

Which of the following is the most ductile metal?AluminiumCopperIronGold