What is the electron arrangement around an atom in a molecule or ion which is surrounded by three lone pairs of electrons and one single bond

Tetrahedral

Explanation:

According to the valence shell electron pair repulsion theory, the number of electron pairs on a molecule determines the arrangement of electrons around the central atom of the molecule or ion.

In this case, there are four electron pairs around the central atom in the molecule or ion hence they are arranged in tetrahedral geometry. Note that the lone pairs only determine the molecular geometry and  not the electron geometry or arrangement.

state the principle of separating two immiscible liquids by separating funnel. describe an activity with diagram to separate a mixture of water and kerosene oil. answer: immiscible layers separate out in layers depending on their densities in separating funne

i'm assuming that the correct answer is indeed the first one/ "a"..