[tÃ¤râ²sÉs] pl. tarsi. Etymology: Gk, tarsos, flat surface. 1 the flat area of articulation between the foot and the leg or the edge of the eyelid. 2 also called tarsal cartilage, tarsal plate. Any one of the fibrous plates of cartilage about 2.5 cm long that form the eyelids. One tarsal plate shapes and gives solidarity to the edge of each eyelid.
Hydrogen is reduced by elements that are less electronegative to form compounds in which its oxidation number is -1. Properties and Formation of Hydrogen. At room temperature, hydrogen is a colorless, odorless gas with a density only one-fourteenth the density of air. Small quantities of H 2 gas can be prepared in several ways. 1.
Obviously, sodium is an extremely reactive metal. When sodium comes into contact with water, it displaces hydrogen gas as follows: 2 Na(s) + 2H 2 O() 2 NaOH(aq) + H 2 (g). This is a dangerous reaction. If the sodium gets hot enough, the hydrogen jets can ignite and burn. That's what caused the sparks you saw. Burning hydrogen makes the temperature rise even faster.