The symbol for the element in period 2, group 13

Iknow the answer to 13 is b and 14 is d. i just need to know why the correct answers are correct

Determine the percent sulfuric acid by mass of a 1.61 m aqueous solution of h2so4. %

Identify one disadvantage to each of the following models of electron configuration: -dot structures -arrow and line diagrams -written electron configurations type in your answer below. (answer) -dot structures do not show the distribution of electrons in orbitals and take up a lot of space. -arrow and line diagrams take up a lot of space and make it difficult to count electrons. -written configurations make it easy to lose count of electrons and do not show the distribution of electrons in orbitals.