Which electron dot diagram below represent a molecule that has a polar covalent bond?

Which of the dna typing techniques do you think you would choose if you had to analyze a dna sample? why?

Asolid that forms and separates from a liquid mixture is called

Sodium sulfate dissolves as follows: na2so4(s) → 2na+(aq) + so42- (aq). how many moles of na2so4 are required to make 1.0 l of solution in which the na concentration is 0.10 m?