18 What is the onerence between metals and romana orm Exam
the basis of the physical properties pick any five physical properties
Answers
Answer:
Physical properties of metal :
(a) State : most of the metals are found solid state at normal temperature except mercury (Hg)Which is found in liquid state at normal temperature.
(b)Colour : Mostly metals are grey in colour.
(c) Lustre : Most of the metals are lustrous. They are capable of reflecting rats of light from their upper surface therefore , they are lustrous such as gold , silver , copper , aluminium.
(d) Hardness : Most of the metals are struck with other hard metals or objects then a special sound i produced , this property is called sonorous.Due to this property of metals they are used to manufacture bell and music instrument etc.
(f) Density : generally metals have high density. things made of metals are heavy so when they put in water they sink while those have less density will float in water such as sodium (Na) and Potassium (K) etc.
(g)Melting point : That temperature at which solid changes into liquid state is called melting point of that object . Due to hardless of solid thier melting point is high such as iron (Fe) .The melting point of iron is 1593
o
C While galium is exception it melts just by putting it on hand palm as its melting point is very low.
(h) Heat conductivity : When a rod of steel is heated , after sometimes it becomes hot while a wooden rod when submerged in hot water does not get heated . Silver (Ag) is the best conductor while lead (Pb) is the least conductor . This is the reason that cooking utensils are made of metals and their handles are made of non-conductors like wood, plastic etc.
1. malleability : metals are spread on beating. hence by the force of hammers they are converted into sheets.
2. Ductility : when they are stretched , convert into wires. this property of metals is called ductility.
(k) Electricity conductivity : metals allow electricity to pass through them. this property is called conductivity of electricity . silver is the best conductor is electricity. hence those objects which are hard, lustrous , sonorous , ductile , malleable, and good conductors of heat and electricity are called metals.
Physical properties of Non-metals :
1. Physical state : They are found three states i.e. solid , liquid and gas at normal temperature such as -solid carbon (C) , Sulphur (S) , Iodine (I), liquid -bromine (Br) and gas oxygen (O
2
), nitrogen (N
2
), hydrogen (H
2
)
2. colour: Non-metals have variety of colours such as sulphur (yellow) chlorine gas (greenish yellow), phosphrous (red, white).
3. Lustre : Non-metls are non lustrous . they do not reflect light . diamond and iodine are exceptions as these are lustrous.
4.Hardness: They are soft . Diamond is exception , it is the hardest nonmetals found on earth.
5. Sonorous : They do not produce sound.
6. Density : They have less density.
7. Melting point : The have low melting point except diamond and graphite .diamond and graphite (isotopes of carbon) have very high melting point.
8. heat and electric conductivity : they are bad conductors of heat and electricity except graphite . it is a good conductor of electricity.
9.Brittle : When they are beaten with hammer, convert into power or pieces it is called brittleness.