12. How many electrons does a neutral atom with 15 protons have

Astudent reacts 13 moles of iron with 21 moles of oxygen according to the following equation:

Sodium nitrite (nano2) reacted with 2−iodooctane to give a mixture of two constitutionally isomeric compounds of molecular formula c8h17no2 in a combined yield of 88%. draw reasonable structures for these two isomers. click the "draw structure" button to launch the drawing utility. place the two compounds in the appropriate boxes below.

Can someone me with 3 and 4 plz. this is for masteries test.