How many atomic orbitals of each type mix to form hybrid orbitals of the central atom in cl2o?

In here Oxygen is the central atom. It makes two bonds with Cl and has two lone pairs. Since, the shape is bent and the hybridization is sp3. Molecular geometry is a bit dissimilar from hybridization. Hybridization is reliant on the number of bonds and lone pairs. Since O has two bonds with Cl, its hybridization is sp3. It is like is this: 1 lone pair/bond = s. 2 lone pairs/bond = sp 3 lone pairs/bonds = sp2, etc. molecular geometry, you count the number of bonds and lone pairs. This has two bonds and 2 lone pairs so if they were all bonds, the molecule would be tetrahedral. 

a rain shadow is a dry region of land on the side that is protected against the prevailing winds of a mountain range. the prevailing winds are the winds that occur most of the time in a particular place of the earth

prevailing winds carry air toward the mountain range. as the air rises up over a mountain range, the air cools, water vapor condenses, and clouds form. on this side of the mountains, called the windward side, precipitation falls in the form of  rain  or snow. this dry air produces a  rain shadow.

c-14 is carbon-14, or radiocarbon.   it is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons.