Question

4. Which gas was used for streetlighting?
5. Name the chemical elements found in coal​ .

Answer 1

Answer:

4)Na vapour used

5) Carbon only

Answer 2

Answer:

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4. Ans:

★Sodium-vapour lamp, electric discharge lamp using ionized sodium, used for street lighting.

★A low-pressure sodium-vapour (LPS) lamp contains an inner discharge tube made of borosilicate glass that is fitted with metal electrodes and filled with neon and argon gas and a little metallic sodium.

5. Ans:

★Hydrogen, oxygen, nitrogen, sulfur, and carbon are found in coal.