What kind of forces act between molecules

Write the chemical symbols for three different atoms or atomic cations with 27 electrons. asap!

How are isotopes of the same chemical element alike? how are they different?

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.