Okumnandi ngengaphakathi layo nokho ubukhulu bayo. Akekho okhala ngokumpintsheka futhi nebhuthi inkulu, ingu-570 litres. Phela uma uthanda uyakwazi ukukhetha elayisha abagibeli abayisikhombisa. The only time it is wrong to use God’s name is if this is done disrespectfully . ​ — Jeremiah 29 : 9 . 8. (a) UJesu wabasiza kanjani abafundi bakhe ukuba babone ukubaluleka koMbuso kaNkulunkulu? (b) Siwusekela kanjani uMbuso kaNkulunkulu namuhla? Definitionboron: Symbol B. An element ofgroup 13 (formerly IIIB) of the periodictable; a.n. 5; r.a.m. 10.81; r.d.2.34–2.37 (amorphous); m.p. 2300°C;b.p. 2550°C. It forms two allotropes;amorphous boron is a brown powderbut metallic boron is black. Themetallic form is very hard (9.3 onMohs’ scale) and is a poor electrical conductor at room temperature. Atleast three crystalline forms are possible;two are rhombohedral and theother tetragonal. The element isnever found free in nature. It occursas orthoboric acid in volcanic springsin Tuscany, as borates in kernite(Na2B4O7.4H2O), and as colemanite(Ca2B6O11.5H2O) in California. Samplesusually contain isotopes in theratio of 19.78% boron–10 to 80.22%boron–11. Extraction is achieved byvapour-phase reduction of borontrichloride with hydrogen on electricallyheated filaments. Amorphousboron can be obtained by reducingthe trioxide with magnesium powder.Boron when heated reacts withoxygen, halogens, oxidizing acids,and hot alkalis. It is used in semiconductorsand in filaments for specializedaerospace applications.Amorphous boron is used in flares,giving a green coloration. The isotopeboron–10 is used in nuclear reactorcontrol rods and shields. Theelement was discovered in 1808 bySir Humphry Davy and by J. L. Gay-Lussac and L. J. Thenard.