Which element makes up approximately 95% or more of the composition of steel?

Which element makes up approximately 95% or more of the composition of steel?

• A. Iron
• B. Carbon
• C. Nickel
• D. Silicon

Answer: (A)

Iron is the main component in steel. Steel is formed as an alloy where iron serves as the base, with carbon and a few other elements added in smaller amounts to change its properties. In most steels, iron makes up about 95% or more of the mass, while carbon is present in a much smaller fraction (enough to alter hardness and strength), and elements like nickel or silicon appear only in small quantities in particular grades. This is why iron is the best answer: it constitutes the overwhelming majority of steel's composition.

Iron is the main component in steel. Steel is formed as an alloy where iron serves as the base, with carbon and a few other elements added in smaller amounts to change its properties. In most steels, iron makes up about 95% or more of the mass, while carbon is present in a much smaller fraction (enough to alter hardness and strength), and elements like nickel or silicon appear only in small quantities in particular grades. This is why iron is the best answer: it constitutes the overwhelming majority of steel's composition.