Final answer:
Boron is used in borosilicate glass, cleaning products like Boraxo soap, and as a material for control rods in nuclear reactors due to its neutron-absorbing properties.
Step-by-step explanation:
The element used in borosilicate glass, Boraxo soap, drill bits, and control rods in nuclear power plants is boron. Borosilicate glass is known for its resistance to thermal shock due to the presence of boric oxide, B₂O₃, which is also used in the production of some optical glasses. Boron filaments are prized for their lightness and strength, finding applications in the aerospace industry, sporting goods, and more. Additionally, sodium tetraborate (borax), is widely employed in fiberglass insulation and in various cleaning products. In nuclear reactors, boron is integral in the manufacture of control rods due to its ability to absorb neutrons, with boron-10 being particularly efficient through a reaction that yields lithium-7 and alpha particles.