How old are the lunar highlands? 1. 1.8 to 2.6 billion years old 2. 3.1 to 3.8 billion years old 3. 4.0 to 4.3 billion years old 4. less than 1 billion years old?

They are about 4.5 billion years old. Hope this helps.

Ch4 and ph3 are both covalent since they are composed both of non-metals.    ch4 is non- polar because of  london forces and has a geometry of tetrahedral  ph3 , on the other hand, is umbrella shaped polar and has dipole-dipole intermolecular force (imf) . since ph3 is polar, it has a stronger imf