Petroleum is a source of energy that is:

Environmental pollution is the effect of undesirable changes in the properties of our air,land,water,or soil that may harmfully affect...

$A$ water sample has $ppm$ level concentration of following anions: $F^{-} = 10 \ ppm$,$SO_4^{2-} = 100 \ ppm$,$NO_3^{-} = 50 \ ppm$. The anion/anions that make the water sample unsuitable for drinking is/are:

Which of the following particle sizes is associated with lung diseases?

Determine whether the following statements are true or false:
$(1)$ The lowest region of the atmosphere where all living organisms,including humans,reside is called the troposphere.
$(2)$ The troposphere extends up to a distance of $25 \ km$ from sea level.
$(3)$ The region between $10 \ km$ and $50 \ km$ from sea level is called the stratosphere.
$(4)$ The ozone layer that protects living organisms is located in the troposphere.

Explain tropospheric pollution caused by oxides of nitrogen.