Question

Calcium, copper, lead, aluminium, zinc, chromium, magnesium and iron.
Choose the major metals from the list given above to make the following alloys:
A. Stainless steel
B. Brass

Answer 1

Alloys are a type of a mixture, containing two or more elements, out of which at least one element is a metal. While making an alloy metals are melted first and then mixed together, followed by cooling so that it becomes solid at room temperature. The common examples of alloys are stainless steel, brass, bronze and sterling silver.

Complete step by step answer:
When two or more elements combine to form an alloy, it results in enhancement of their properties. The alloy generally has metallic properties.
Here, a list of metals is given and we have to select the major metals involved in the preparation of given alloys.
Let us first understand the important terms related to an alloy.
The parent metal is the major metal present in that alloy. It can also be termed as main metal or base metal. The rest of the elements present in an alloy are referred to as the alloying agents. An alloying agent is a metal or non-metal and present in a very small quantity in the alloy.
Stainless steel: The stainless steel is an alloy of iron. It is composed of $80 - 85\%$ iron ($Fe$) and minimum $10.5\%$ chromium ($Cr$). Therefore, the parent metal in stainless steel is iron. It is corrosion resistant and has very good fire resistant properties as compared to the other materials.
Hence, the major metals present in stainless steel are iron and chromium.
Brass: The brass is an alloy of copper ($Cu$) and zinc ($Zn$). It contains copper in the range of $55 - 95\%$ and the amount of zinc ranges from $5 - 45\%$. The parent metal in brass is copper. The basic brass is composed of $67\%$ copper and $33\%$ zinc. Brass is malleable and generally used in musical instruments.
Hence, the major metals present in brass are copper and zinc.

Additional information:
Alloys are classified into two types:
1.Substitution alloys
2.Interstitial alloys
In substitution alloy, the main metal atoms are replaced by the atoms of the alloying agent while combining molten metals with alloying agents. Brass is an example of substitution alloy.
In interstitial alloy, the atoms of alloying agents are very small in size than the main metal atoms and fits into the gaps between the main metal atoms. Stainless steel is an interstitial alloy.

Note: Though the major metals present in stainless steel are iron and chromium, it also contains carbon along with other elements. The amount of carbon present in the stainless steel is varied. Also other elements such as nickel, molybdenum, titanium, manganese are added in stainless steel to enhance its properties.
In brass, lead ($Pb$) is also added in very small quantities in order to enhance the properties of brass.