classify as physical or chemical change. give reason
1) metal oxides dissolving in water to form alkalis
2)mettalic sodium is soft enough to be cut with a knife
3) cuttiing of trees
classify as physical or chemical change. give reason
1) metal oxides dissolving in water to form alkalis
2)mettalic sodium is soft enough to be cut with a knife
3) cuttiing of trees
Physical change involves change in one or more physical properties of matter.There is no change in the chemical composition and property of the matter.It is generally reversible.
Whereas, a chemical change involves change in the chemical composition and chemical properties of the matter.It involves formation of a new kind of matter and the process is irreversible.
1) metal oxides dissolving in water to form alkalies :
When a metal oxide reacts with water, it results in the formation of an alkali. Metal oxide has different chemical properties from that of base . Since there is a change in the properties of the matter thus it is a chemical reaction.
For eg.
K2O + H2O2 KOH
2)Metalic sodium is soft enough to be cut with a knife
when sodium is cut with a knife, only its size change. There is no change in the chemical properties of sodium. Thus it is a physical change.
3)Cutting of trees
Cutting of trees is a physical change since it does not change the chemical properties of tree and its components. However since trees are living thus when they are cut, a series of chemical reactions undergoing in a tree are stopped.
Physical change involves change in one or more physical properties of matter.There is no change in the chemical composition and property of the matter.It is generally reversible.
Whereas, a chemical change involves change in the chemical composition and chemical properties of the matter.It involves formation of a new kind of matter and the process is irreversible.
1) metal oxides dissolving in water to form alkalies :
When a metal oxide reacts with water, it results in the formation of an alkali. Metal oxide has different chemical properties from that of base . Since there is a change in the properties of the matter thus it is a chemical reaction.
For eg.
K2O + H2O2 KOH
2)Metalic sodium is soft enough to be cut with a knife
when sodium is cut with a knife, only its size change. There is no change in the chemical properties of sodium. Thus it is a physical change.
3)Cutting of trees
Cutting of trees is a physical change since it does not change the chemical properties of tree and its components. However since trees are living thus when they are cut, a series of chemical reactions undergoing in a tree are stopped.
