Which of these pairs of elements have the same number of valence electrons? a. phosphorus (p) and chlorine (cl) b. berylium (be) and calcium (ca) c. chlorine (cl) and helium (he) d. oxygen (o) and carbon (c)

What is the independent variable in this investigation? mass volume sample number substance density

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.

What must occur for air masses to form fronts