Name the petroleum product for surfacing roads.

The petroleum product used for surfacing roads is bitumen.

Complete step-by-step solution –

Bitumen is a thick, black, and sticky liquid or semi-solid form of petroleum.

It is obtained as a residue during the refining of crude oil. After lighter fractions like petrol, diesel, and kerosene are separated, bitumen is left behind.

It is waterproof, strong, and resistant to wear, which makes it suitable for road construction.

When mixed with small stones and gravel, it forms a smooth, hard surface that can bear heavy traffic.

Bitumen is also flexible, so it can adjust to slight movements in the ground without cracking.

Additional Information:

Apart from road surfacing, bitumen is used in roofing, waterproofing, and making paints and varnishes.

In some places, coal tar (another petroleum by-product) was earlier used, but bitumen is now preferred because it causes less pollution and is more durable.

Note: The use of bitumen has greatly improved the quality of modern roads, making them smoother and longer-lasting compared to old mud or gravel roads.