Tip of the red-giant branch result is a sharp discontinuity in the evolutionary track of the star on the HR diagram. This discontinuity is called the tip of the red-giant branch. When distant stars at the TRGB are measured in the I-band (in the infrared), their luminosity is somewhat insensitive to their composition of elements heavier than helium (metallicity) or their mass; they are a standard candle with an I-band absolute magnitude of –4.0±0.1. This makes the technique especially useful as a distance indicator. The TRGB indicator uses stars in the old stellar populations (Population II). Tip of the red-giant branch Tip of the red-giant
Hydrogen sulfide sulfide solution. Hydrogen sulfide generated in this process is typically converted to elemental sulfur using the Claus Process. Hydrogen sulfide is a highly toxic and flammable gas (flammable range: 4.3–46%). Being heavier than air, it tends to accumulate at the bottom of poorly ventilated spaces. Although very pungent at first, it quickly deadens the sense of smell, so victims may be unaware of its presence until it is too late. For safe handling procedures, a hydrogen sulfide safety data sheet (SDS) should be consulted. Hydrogen sulfide is a broad-spectrum poison, meaning that it can poison several different systems in the