What is the geometry of a ClF3 molecule? (AQA Unit 1 2015 1d)

Chlorine, Cl, and Florine, F are both in group 7 of the periodic table so they have 7 electrons in the outer energy level, called valence electrons. Each fluorine atom makes one covalent bond to the chlorine atom so 1 more electron is added to the outer energy level for each. Now there are 7 + 3 = 10 valence electrons. But each covalent bond is made by sharing a pair of electrons so dividing 10 by 2 gives the number of pairs of electrons. 10 / 2 = 5. So there are 5 pairs of valence electrons. The 5 pairs of electrons will arrange themselves around the atom to get as far apart as possible because they repel each other. This leads to a shape called a trigonal bipyramid which has angles of 90 and 120 degrees between bonds. However, there are only 3 bonds to other atoms so there must be 2 lone pairs. 5 - 3 = 2. The geometry will still be approximately the same but there will be some atoms missing from the shape. Lone pairs repel each other more than bonding pairs do, so they are placed furthest from other atoms. In the trigonal bipyramid shape this is in the triangle of the pyramid so the shape in the end is a t-shape with bond angles of 90 degrees.