Consider the following statements : 1. Coal ash contains arsenic, lead and mercury. 2. Coal-fired power plants release sulphur dioxide and oxides of nitrogen into the environment. 3. High ash content is observed in Indian coal. Which of the statements given above is/are correct ?

Defines fly ash as the fine residue produced when solid fuel combustion occurs and distinguishes it from bottom ash.

A student can infer that any elements present in coal may be partitioned into fly ash during combustion and then check external sources for which trace elements typically occur in coal/ash (e.g., arsenic, lead, mercury).

States that Indian coal contains a substantial percentage of ash (20–30%), showing that coal inherently contains noncombustible mineral matter.

Given high ash content, a student could reasonably expect minerals and associated trace elements to be present in the ash and then look up common trace metals associated with coal mineral matter.

Gives examples of coals with very high ash fractions (e.g., 35% ash), reinforcing that combustion yields significant residual ash from coal.

High ash fractions make it plausible that trace constituents in the original coal will be concentrated in the ash; a student can use that to justify checking analytical data on ash composition for specific metals.

Explains coal types and notes lower-rank coals (lignite) have high ash content, indicating variability in ash-producing potential among coals.

A student can combine this with knowledge of coal type distribution to predict which ashes are more likely to concentrate impurities and then consult chemical analyses for those ashes.

Notes health effects (pneumoconiosis) from coal dust exposure, implying coal and its residues can carry harmful substances affecting health.

While not naming metals, this suggests coal-related materials can be hazardous; a student could therefore reasonably investigate whether toxic elements (like arsenic, lead, mercury) are among those hazards in ash.