The presence of harmful substances in the air is called / the answer here/ . polluted air indoors or outdoors can be /the answer here/ to a person’s health, and can have many negative environmental effects. air pollution can also lead to
/the answer here/

beneficial, climate change, air erosion, air pollution, hazardous, oxygen /these are the answers to pick out of from/

Indoor pollution can be reduced by reducing the main causes of this pollution which are: avoid smoking indoor, reducing use of carpeted floors, proper ventilation,    keep trash baskets covered, minimizing the use of air-fresheners and irritating perfumes, use exhaust fans. The outdoor pollution can be reduced by minimizing the use of vehicles whose burning fuel contribute a lot to outdoor air pollution, the chimneys of industries and factories should have filters fixed in so that harmful substances may not be exposed to air.

  the grams     of oxygen gas   that can be produced     is 20.6   grams of o₂

calculation

2liclo₃ →   2 licl + 3 o₂

step 1:   find the moles of liclo₃

moles = mass÷ molar mass

from periodic table the molar mass of liclo₃ =6.9 +35.5   +(16 x3) =90.4 g/mol

moles=38.7 g÷90.4 g/mol=0.4281   moles

step 2:   use the   mole ratio   to calculate the moles of o2

from equation above, liclo₃: o₂   is 2: 3  

therefore the moles of   o₂=0.4281 moles x3/2 =0.6422   moles

step 3: find mass   of o₂

mass= moles x molar mass

from periodic table the   molar mass of   o₂ = 16 x2= 32 g/mol

mass=0.6422   moles   x   32 g/mol = 20.6 grams of o₂