41. Metalloids have properties of both metals and nonmetals, but the term'metalloid 'lacks a strict definition. 42. In 1811, Berzelius referred to nonmetallic elements as metalloids , in reference to their ability to form oxyanions. 43. The greater propriety of applying the word metalloid to other elements, such as arsenic, had been considered. 44. They can also form Zintl phases ( half-metallic compounds formed between highly electronegative metals or metalloids ). 45. Cys-113 and Cys-422 have been shown to form a high-affinity metalloid binding site. 46. Silicon is a metalloid , readily donating or sharing its four outer electrons, and it typically forms four bonds. 47. Certain elements such as silicon sometimes resemble metals and sometimes resemble non-metals, and are known as metalloids . 48. As with all the elements commonly recognised as metalloids , germanium has an established organometallic chemistry ( see organogermanium chemistry ). 49. It has been referred to as either a very poor metal, a metalloid , a nonmetal or a near metalloid. 50. It has been referred to as either a very poor metal, a metalloid, a nonmetal or a near metalloid .