What is the molecular geometry around a central atom that is sp3d hybridized and has three sigma bonds and two lone electron-pairs?

What is the ph of a solution that has a hydrogen ion concentration of 1.0 * 10 -9 m?

In the diagram here that represents the reaction, which reactant, a or b, is the limiting reagent?

Astable atom that has a large nucleus most likely contains 1. more neutrons than protons. 2.more protons than neutrons. 3.equal numbers of protons and neutrons. 4.changing numbers of protons and neutrons.