Alloys and their properties - class-XII

Gold as pure metal is too soft on its own and is therefore hardened by the addition of alloying element like silver for ornamental purpose.
option A is correct.

The mix of two or more metals is called an alloy. the various properties of metals can be unproved by mixing two or more metals.

Nickel steel is commonly used for automobile parts and utensils due to its high strength, toughness, and resistance to corrosion.

Solder- an alloy of tin $(Sn)$ and lead $(Pb)$
Bronze-an alloy of copper $(Cu)$ and tin $(Sn)$
Brass-an alloy of copper $(Cu)$ and Zinc $(Zn)$
Bell metal-an alloy of copper $(Cu)$ and tin $(Sn)$
Therefore option A is correct

Making iron is the first step of production of steel. Iron is usually made from iron ore,limestone and coal. Limestone is added to iron before entering the blast furnace. The limestone reacts with acidic impurities called slag and floats on top of the molten iron where it is skimmed off.

Stainless steel also known as inox steel. It is an alloy of steel (Iron and nickel) with chromium 10.5%. It does not corrode readily, rust or stain. There are different grades of stainless steel. It is used where both the properties of steel and corrosion resistance are required.

Alloys have properties which can different from the constituent metals. In fact it is possible to make alloys having required properties.

Amalgam is a substance formed by the reaction of mercury with another metal.Almost all metals form amalgams with mercury with exceptions being iron,platinum,tungsten and tantalum.Silver-mercury amalgams are important in dentistry.

Bronze is an alloy of $Cu$ and $Sn$. It does not contain zinc metal.

Solder is an alloy of Sn and Pb which makes alloy with high corrosion resistance.

Galvanization or galvanizing is the process of applying a protective zinc coating to steel or iron, to prevent rusting. The most common method is hot-dip galvanizing, in which the parts are submerged in a bath of molten zinc.

An alloy is a homogenous mixture of two or more metals or non metals or nonmetals mixed in a molten state.

Only chromium is not an alloy.
Constantan is a copper–nickel alloy.
Manganin is an alloy of  86% copper, 12% manganese, and 2% nickel.
Nichrome is an alloy of nickel, chromium.

The most common material used in building cars is Steel because it is strong, easy to work with, cheap, readily available and almost every car will have some steel in it. 

101652

1) Cu, Sn and Zn.

2) Gunmetal, also known as red brass, is a type of bronze – an alloy of copper, tin, and zinc.

3) Gunmetal can also mean steel treated to simulate gunmetal bronze.

Annealing is the process of heating the steel to high temperature to soften it and it undergoes three phases. Quenching involves heating the steel and tempering in water or oil. This rapid cooling results in hard and brittle steel.

An alloy is a homogeneous mixture of two or more metals in a definite proportion. 

Steel is an alloy primarily composed of iron and carbon, where carbon is a non-metal. The other options, bell metal, bronze, and invar, are alloys consisting solely of metallic elements like copper, tin, nickel, and iron.

Spiegeleisen is a ferromanganese alloy.
It contains iron, manganese and carbon.
Manganese is present to about 15%.

In a ccp lattice, Cu atoms at corners and faces give 4 atoms per unit cell. Silver atoms at edge centers (12 edges * 1/4 = 3 atoms). Gold at body center (1 atom). Formula: Cu4Ag3Au.

Bell metal is a hard alloy used for making bells and similar instruments, consisting primarily of copper and tin. Therefore, the combination of Cu and Sn is the correct chemical composition for bell metal.

22 karat gold contains 22 parts gold and 2 parts of other metals added as alloy. ... 18 karat gold contains 18 parts pure gold with 6 parts of other metals added. In the West the karat is expressed in fineness.

Bell metal is a hard alloy used for making bells and related instruments, such as cymbals. It is a form of bronze, usually approximately 4:1 ratio of copper to tin (e.g., 78% copper, 22% tin by mass).

Iron (Fe) and Mercury (Hg) do not form an alloy because iron does not dissolve in mercury. The other pairs listed are common components of various alloys.

a. An increasing or decreasing temperature doesn't affect mass. Mass is the amount of matter in an object whereas temperature is the human sense of kinetic energy of matter. Thermal energy is very, very, very small, so no, it is not measurable as mass.

b. Plasma is the fourth state of matter. Plasma is an ionized gas, a gas into which sufficient energy is provided to free electrons from atoms or molecules and to allow both species, ions and electrons, to coexist.

c. An alloy is a homogeneous mixture of 2 or more metals or metal with 2 or more semi-metals.

d. It is homogeneous because the additions take place in the liquid state, so the atoms mingle with each other and mix thoroughly.

An alloy is a material composed of two or more metals or a metal and a nonmetal. An alloy may be a solid solution of the elements (a single phase), a mixture of metallic phases (two or more solutions) or an intermetallic compound with no distinct boundary between the phases. Solid solution alloys give a single solid phase microstructure, while partial solutions exhibit two or more phases that may or may not be homogeneous in distribution, depending on the thermal (heat treatment) history of the material. An inter-metallic compound has one other alloy or pure metal embedded within another pure metal.

The term alloy is used to describe a mixture of atoms in which the primary constituent is a metal. The primary metal is called the base, the matrix, or the solvent.

Both Statement 1 and
Statement 2 is correct and Statement 2 is the correct explanation of
Statement 1.

Tinning is the process of thinly coating sheets of wroughtiron or steel with tin, and the resulting product is known as tinplate. While once more widely used, the primary use of tinplate now is the manufacture of tin cans. Formerly, tinplate was used for cheap pots, pans and other holloware. It has an extremely beautiful metallic luster as well as excellent properties in corrosion resistance, solderability, and weldability. 

A fusible alloy is a metal alloy capable of being easily fused, i.e. easily meltable, at relatively low temperatures. The most widely used fusible alloys contain high percentages of bismuth, combined with lead, tin, cadmium, indium and other metals. Bismuth has an impact on the melting point, as well as the growth and shrinkage characteristics of the alloys.

Bronze is an alloy consisting primarily of copper, commonly with about 12% tin and often with the addition of other metals (such as aluminium, manganese, nickel or zinc) and sometimes non-metals or metalloids such as arsenic, phosphorus or silicon.

Alloys are metallic materials consisting of two or more elements combined in such a way that they cannot be readily separated by physical means. More than 90% of metals used are in the form of alloys.

An alloy is a mixture of two or more metals. Thus, it is solid in solid.

Bronze is an alloy consisting primarily of copper, commonly with about 12% tin and often with the addition of other metals (such as aluminium, manganese, nickel or zinc) and sometimes non-metals or metalloids such as arsenic, phosphorus or silicon.

Type metal is an alloy of lead, tin and antimony in different proportions depending on the application, be it individual character mechanical casting for hand setting, mechanical line casting or individual character mechanical typesetting and stereo plate casting.

Answ: (A) Alloys

Ans : (A) An alloy is a mixture of various metals that can also contain non-metals elements.

Both statement right and statement $2$ are correct Explanation.

Ans: (B) Smaller atoms of one metal are incorporated into the structure of large metal atom to redue malleability and improve strength of structure.

Alloys of mercury with metals like silver, copper, tin, zinc are used as amalgams.

Monel is a group of nickel alloys, primarily composed of nickel (up to 67%) and copper, with small amounts of iron, manganese, carbon, and silicon. Stronger than pure nickel, Monel alloys are resistant to corrosion by many agents, including rapidly flowing seawater.

 Brass for articles like bangles and utensils.

Molybdenum can be obtained from the minerals molybdenite, wulfenite and powellite. It is also obtained as a byproduct during tungsten and copper mining and processing. It has one of the highest melting points of all pure elements; however it is not resistant to acids.Hence, molybdenum steel is also not resistant to acids.