Chemistry Project – Physical and Chemical Properties of Metals and Non-Metals
Contents: Physical properties of Metals Chemical properties of Metals Physical properties of Non-Metals Chemical properties of Non-Metals
PHYSICAL PROPERTIES OF METALS
Physical properties of Metals: Physical properties are an important way of distinguishing one material to another. In the study and application of metallurgy (study of physical and chemical behaviour of metallic elements), physical properties are often considered a broader category than mechanical properties, but not all properties overlap. Physical properties are most easily distinguished from mechanical properties by the method of testing. While mechanical properties require force to be applied to obtain a measurement, physical properties can be measured without changing the material.
Physical properties do change in different environments. For example, most metals have a higher density at lower temperatures due to the principles of thermal expansion (tendency of matter to change it’s shape, area, volume & density in response to a change in temperature) and contraction (the decrease in size of atoms and ions on the elements). Colour and appearance, which are also physical properties, change based on a number of environmental properties .
Physical properties of metals include: Corrosion Resistance Density Melting Point Thermal Properties: Heat Capacity Thermal Conductivity Thermal Expansion Electrical Conductivity Magnetic Properties
Corrosion Resistance: Corrosion is a process in which a material is reduced to a more stable state by chemical reaction, often related to the atmosphere service conditions. Many types of corrosion occur. Rust, a common sight on the unprotected products made of ferrous metals, is one of the most common forms of corrosion. Corrosion resistance , on the other hand, is the material’s ability to resist the reaction to move towards a more stable state in its environment. Raw aluminium, silicon, titanium and their alloys are naturally corrosion resistant due to an unreactive layer that quickly forms on their surfaces. A common alloy for many applications requiring corrosion resistant is stainless steel. Unlike carbon steel, stainless steel alloys are able to resist surface corrosion when exposed to environments that would normally cause corrosion, including wet, acidic or high heat.
Density: The density of an object is determined by a simple formula: the object’s mass (M) divided by it’s volume (V). At first, the practical application of density was to determine the authenticity (quality) of gold, as in the story of the golden crown. Gold is an excellent candidate for testing density, because it is a much denser material than other metals, with an average density of 1,206 lbs (547 kg). per cubic foot. Alloys more commonly used in manufacturing have lower densities. Steel averages around 494 lbs (224 kg). per cubic foot, while stainless steel is a bit less.Titanium is about half the density of steel and aluminium is about one-third. Practically speaking, this means that a part made of steel will weigh approximately three times more than the exact same part of aluminium. However, steel has other advantages like hardness and strength, and so lower volumes or thicknesses of material can provide the same or better performance, comparatively. Eagle Alloy and Eagle Precision often produce complex, thin-walled castings from different carbon and stainless steel alloys. The alloy affects the design, production process and finishing techniques used to manufacture each cast part.
Melting Point: The melting point of a material is defined as the temperature in which it changes form solid to liquid at atmospheric pressure. Melting point can be a major factor in deciding if an alloy will be possible to use for particular product. Different alloys have different melting point ranges, as determined by the elements of their chemical makeup. For example, an alloy with a high percentage of tin or aluminium will melt at a much lower temperature than an alloy made of mostly tin and nickel. Melting point is an important consideration for metal manufactures. Many casting facilities utilize sand casting methods like air set or shell mould casting because the non-metal modes can withstand higher temperatures required to metal steel. Aluminium, on the other hand, can be cast using reusable steel moulds, since it has a much lower melting point than steel.
Chemical properties of Metals
Chemical properties of Metals: The density of metals usually high. Metals are malleable and ductile Metals form an alloy with other metals or non – metals. Some metals react with air and corrode. For e.g. Iron. Metals are good conductors of electricity. Lead is an exception. Generally, metals are in solid state at room temparature Except for Mercury, as it is in a liquid state. Many metals produce metal oxide by burning in the oxygen of the air. Highly reactive metals react violently when they’re burnt in oxygen . Metals like sodium and potassium are stored in oil as they react with air in seconds. They’re highly reactive metals. Less reactive metals like gold, silver, platinum, etc do not tarnish easily. They stay shiny and lustrous . Metals produce metal oxide and hydrogen gas while reacting with water.
Soluble metal oxides dissolve in water and create metal hydroxide. Not all metals react with water. However , highly reactive metals like sodium and potassium react with water violently and an exothermic reaction takes places where the hydrogen immediately catches fire . Salt and hydrogen are produced when a metal reacts with an acid . Generally, a metal displaces a less reactive metal in a metal salt solution.
Physical properties of Non-Metals
Physical properties of Non-Metals: Non-metals have high ionization energies. They have high electro negativities . Non-metals are insulators which means that they’re poor conductors of electricity. They are dull, they do not have lustre like metals. Non-metals are poor conductors of heat. They’re poor thermal conductors. They are very weak and brittle. They tend to easily break or shatter. Non-metals have a low density. They’re light for their size. They aren’t good conductors of sound and do not make sounds when they are hit. They tend to gain electrons easily. Non-metals maybe solid, liquids or gaseous. Non-metals form acidic oxides. They’re good oxidizing agents. Generally, Non-metals have four to eight electrons in the outer shell.
Chemical properties of Non-Metals
Chemical properties of Non-Metals : Non-metals are poor conductors of heat and electricity. Graphite and Gas carbon are exceptions. Unlike metals, non-metals aren’t malleable and ductile. Non-metals react more with metals than with non-metals. Usually, non-metals react with other non-metals in high temperature. Most non-metals do not react with air in room temperature. White phosphorus is the only non-metals that reacts with air to form its oxide by burning. Usually, non-metals do not react with water. Except for Chlorine, chlorine dissolves in water to form an acidic solution. Non-metals have a low density. They do not form alloys. However, non-metals like carbon, silicon and phosphorous. Non-metals exist in all states of matter at room temperature. Different non-metals have different reactions. Chlorine is the most reactive metal in the halogen family i.e. Chlorine ( Cl ), Bromine (Br), Iodine (I), and Fluorine (F). The reactivity order of the halogen family is Cl > Br > I. Therefore, Chlorine ( Cl ) can displace Bromine (Br) and Iodine (I) from solutions of bromides ( NaBr ) and Iodides ( NaI ). Ionic solids are formed when non-metals with high electro negativity react with alkali and alkaline earth metals.