iron mixed with carbon to form steel and it is considered a physical change. why?
Answers
Answer:
Combined with varying (but tiny) amounts of carbon, iron makes a much stronger material called steel, used in a huge range of human-made objects, from cutlery to warships, skyscrapers, and space rockets. Let's take a closer look at these two superb materials and find out what makes them so popular!
Answer:
You might think of iron as a hard, strong metal tough enough to support bridges and buildings, but that's not pure iron. What we have there is alloys of iron (iron combined with carbon and other elements), which we'll explain in more detail in a moment. Pure iron is a different matter altogether. Consider its physical properties (how it behaves by itself) and its chemical properties (how it combines and reacts with other elements and compounds).The reason we so rarely see pure iron is that it combines readily with oxygen (from the air). Indeed, iron's major drawback as a construction material is that it reacts with moist air (in a process called corrosion) to form the flaky, reddish-brown oxide we call rust. Iron reacts in lots of other ways too—with elements ranging from carbon, sulfur, and silicon to halogens such as chlorine.
Explanation:
Think of the greatest structures of the 19th century—the Eiffel Tower, the Capitol, the Statue of Liberty—and you'll be thinking of iron. The fourth most common element in Earth's crust, iron has been in widespread use now for about 6000 years. Hugely versatile, and one of the strongest and cheapest metals, it became an important building block of the Industrial Revolution, but it's also an essential element in plant and animal life.