⚫Metals and nonmetals
Friends today we are going to learn a very useful lesson name is metals and nonmetals. Basically in this topic we will talk about the definition of metals and nonmetals with suitable examples, physical properties of metal and non metals and difference between metals and nonmetals.
⚫What are metals ?give some examples.
Metals are those having properties such as lustre, hardness and conductor of heat and electricity.
Examples: gold, copper ,iron ,silver magnesium, calcium, sodium ,aluminium and platinum
⚫What are physical properties of metals?
Basically most of the metal looks lustrous. That means they have the shinning property. When the light falls on the surface of metal it gets reflected.
Normally at room temperature metals are found in solid state. However some metals like gallium and mercury are the exception. These metals are found in liquid state even at the room temperature.
Generally most of the metals are hard means tough. But there are some exceptions like sodium and potassium which are very soft and can be easily cut by knife.
Ductility means wire can be drawn from most of the metals like gold or silver.
Normally when metal ( iron nail) is hammered we will get sheet .this property is called malleability of metals
➡️Conduction of heat
When one end of any metals are heated other ends also get heated. That means heat is flowing from one end to other end of the metal. Metals like copper, aluminium and silver are best conductor of heat.
➡️Conduction of electricity
Copper wires are responsible for carrying electricity from one point to another point. It means that metals are also have the property of conduction of electricity
Density of most of the metals are very high but in some exceptions like sodium lithium and potassium they have the lower density with respect to water. Density of lithium is 0.5 gram per cc
➡️Melting and boiling point.
Most of the metals have very high melting and boiling point but there are some exceptions also like mercury gallium, potassium ,sodium
When the metals are hit they produce the sound, it means that metals are sonorous in nature
⚫Chemical properties of metals
With respect to electronic configuration ,metals have up to 3 electrons in their last shell.
Sodium have one electron, magnesium have two electron, and Aluminium have 3 electrons in the outermost shell.
|Metal||Atomic number||Electronic cofiguration|
➡️Formation of ions
Since the metals have up to 3 electrons means 1 ,2 and 3 electrons in the outermost shell.theycan easily lose these electrons.
Sodium can lose one electron and form +1 charge,magnesium can lose two electrons and form+2 charge
And Aluminium can lose 3 electrons and they form +3 ions.
Na ➡️ Na++1e–
Mg ➡️ Mg+++2 e–
Al ➡️ Al++++ 3 e–
➡️Reaction with oxygen
Metals when combine with oxygen to form metal oxide
Na+o2 ➡️ Na2o
This metal oxide is basic in nature and on combining with acid form salt and water
➡️Reaction with acid
When most of the metal react with dilute acid they form salt and hydrogen gas is given out
Metal+dilute acid=salt+hydrogen gas
➡️Reaction with water
Mostly most of the metal do not react with cold water but there are some metals like sodium and potassium when they reacted with the cold water they form the hydroxide and hydrogen gas
Magnesium metal require steam for such type of reactions
⚫What are non metals? Give some examples.
Non metals are those that do not have properties like lusture, hardness and conduction of heat and electricity.
Phosphorus, Sulphur, carbon
⚫What are physical properties of nonmetals?
Basically non metals do not show the lustrous properties like metal. But there are some exception like diamond in iodine which are non metal Still they showing the lusture properties.
normal at room temperature most of the non metals are found in solid, liquid and gases state.
Carbon ,Sulphur and phosphorus are found in solid state .bromine is liquid state .hydrogen ,nitrogen and oxygens are found in gaseous state.
➡️Malleability and ductility
Non metals are neither malleable nor ductile.
➡️ Conduction of heat and electricity
basically non metals are bad conductor of heat and electricity except graphite which is a allotrope of carbon is found to be a good conductor of heat and electricity.
They have lesser density.
➡️ Melting and boiling point
melting and boiling points of non metals are low.
There is an exception like carbon and boron which melt at high temperature.
⚫What are metalloids ? Give some examples
Metalloids are those which represent properties intermediate between metals and nonmetals .
Germanium (Ge), silicon (Si), arsenic(As),antimony(Sb) and Bismuth (Bi)are some of the example of metalloids
⚫Chemical properties of nonmetals
Most of the non metals have 5 ,6 and 7 electrons in their last shell. To make outermost shell as Octet i.e 8 electrons in the outermost shell, they take the electron from other element.
Phosphorus has five electrons in the outermost shell ,it can take three more electrons from the other element to complete octet.
Similarly sulphur has 6 electrons in the last shell, it can take two electrons from the other element to complete octet.
|Nonmetal||Atomic Number||Electronic Configuration|
⚫Formation of ions
Since Phosphorus has five electrons in the last shell , it takes three electron from other element and form (-3)negative charge.
Similarly chlorine has 7 electron in its outermost shell, it can take one electron from the other element and form -1 charge.
➡️Reaction with oxygen.
Non metals on reacting with oxygen they form their respective oxides
Nonmetals+oxygen=non metal oxides
C+O2 ➡️ CO2
CO2 +H2O ➡️ H2CO3(Carbonic acid)
SO2+H2O ➡️ H2SO3(Sulphurus acid)
SO3+H2O ➡️ H2SO4 (Sulphuric acid)
➡️ Reaction with acid
Non metal does not show any remarkable reaction with the dilute acids like HCl and HNO3.
⚫What are differences between metals and nonmetals?
|1||Good cundoctor of heat & electricity||bad cundoctor of heat & electricity|
|3||High melting & boiling point||Low melting & boiling point|
|4||Malleable & ductile||Non Malleable &non ductile|
|6||High density||Low density|
⚫What are noble metals? Give some examples
There are some metals which are found in the elemental state.
Silver, platinum ,palladium and rhodium. Gold is a noble metal which is found as a purest form that is also known as 24 carat gold. Some metal which are found in the elemental as as well as parent form is called as noble metal which does not react with other metal and nonmetal.
⚫ Keep in mind
Goldsmith mix pure gold with some copper or silver so that it cannot be broken down because pure gold is very soft. Ornaments are also made from 22 carats gold,
⚫What are uses of nonmetals
➡️ To make ornaments
➡️ To make electronic devices
➡️ Platinum palladium are used as a catalyst.
➡️ Silver is used in medicine because it has some antibacterial property
⚫Purity of gold
⚫What is corrosion?
Sometimes surface of most of the metal gets affected by the gases and moisture present in the atmosphere this is called as corrosion.
Statue of Liberty which is in New York city in America was made from copper. Now a days its surface are looking like green which is bbecause of the reaction of copper with the carbon dioxide and moisture present in the air to form copper carbonate.
Similarly a reddish coloured deposits which is formed on the iron by the reaction of oxygen moisture present in the air is also and good example of corrosion
⚫How to prevent corrosion?
It can be prevented when the layer of oil, grease varnishes and paints are applied on the metal surface
It is basically a homogeneous mixture of two or more metals or homogeneous mixture of metal with nonmetal
Stainless steel utensils are used at home which is made up of alloy of iron with carbon, chromium and nickel
Bronze is formed from copper and tin
⚫Do you know that?
Qutub minar in Delhi about 1500 year ago. The pillar is still showing a lustrous property after so many years because the ancestors had made it from alloy. It contains small proportion of carbon ,silicon and Phosphorus mix with iron.