Tetrahedron generally known as triangular pyramid consists of 4 triangular faces, 6 edges and 4 vertices. The base of the tetrahedron is a triangle. All the vertices have the same atom that is bonded to the central metal atom which lies in the centre of the tetrahedron. We take ![[SiO_4]^4^-](https://tex.z-dn.net/?f=%5BSiO_4%5D%5E4%5E-)
as an example to see how the atoms actually bond in tetrahedron. It is quite visible from the image that 4 O-atoms lies on all the 4 vertices and 1 Si-atom lie in the centre.
The answer is c. the others are compounds.
the nucleus is an organelle containing the cell's chromosomes
1. all elements are made of small particles called atoms
2. atoms of one element are identical in their properties, different atoms from different elements differ in properties
3. chemical reactions consist of atoms rearranging in whole number ratios
4. atoms can not be subdivided, created, or destroyed
