Answer:
Silicon with symbol Si.
Explanation:
The metalloids; boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te), polonium (Po) and astatine (At) are the elements found along the step like line between metals and non-metals of the periodic table.
They have 4 valence electrons in their outermost shell.
The one in period 3 is one with atomic number of 14 and electronic configuration of 2:8:4.
This element is Silicon with symbol Si.
It is a chemical element with the symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic lustre, and is a tetravalent metalloid and semiconductor.
Silicon is one of man's most useful elements. In the form of sand and clay it is used to make concrete and brick; it is a useful refractory material for high-temperature work, and in the form of silicates it is used in making enamels, pottery, etc.
I hope this was helpful, please rate as brainliest
