Question

write three uses of hydrogen and silicon

Answer 1

HYDROGEN:
1.the chemical industry it is used to make ammonia for agricultural fertiliser.
2.It is also used to remove sulfur from fuels during the oil-refining process.
3.used in rocket fuel.

SILICON:
1.used in making solar cells with silver.
2.used extensively as a semiconductor in solid-state devices in the computer and microelectronics industries. 
3.silicon is used to make glass.
4.it is  used to make pottery. 

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Answer 2

HYDROGEN

1. Liquid Hydrogen is used as fuel in rockets.

2. Hydrogen is used to form many compounds.

3. Hydrogen is used in reduction of metallic ores.

SILICON

1. Silicon is used to make alloys including aluminium-silicon and ferro-silicon (iron-silicon).

2. Silicone oil is a lubricant and is added to some cosmetics and hair conditioners.

3. Silicon carbides are important abrasives and are also used in lasers.