Theory:

When a material undergoes a chemical change or reaction, the chemical property is a trait or activity that can be observed. Chemical properties may be detected during or after the reaction since the arrangement of atoms inside a sample must be disrupted to analyse the property.
 
Let us see some of the physical properties of Non-metals:
 
Reaction with Oxygen:
  
Non-metals react with oxygen to form oxides.
Nonmetal+OxygenOxideC+O2CO2
 
Reaction with Water:
  
Non-metals do not react with water, but they are very reactive in air.
Nonmetal+WaterNoreactionN+H2ONoreaction
 
Reaction with Acid:
  
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Non-metals on reaction with acid
 
Non-metals do not react with dilute mineral acids but react with conc. sulphuric acids.
Nonmetal+AcidNoreactionS+HClNoreaction
 
Reaction with Base:
  
Non-metals react with bases to form salt and water.
Nonmetal+BaseSalt+WaterCl2+Ca(OH)2Ca(OCl)Cl+H2O
 
Displacement reaction: More reactive non-metal replaces a less reactive non-metal from its compound.
 
Morereactivenonmetal+lessreactivenonmetalcompoundMorereactivenonmetalcompound+LessreactivenonmetalCl2+2KBr2KCl+Br2
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