Water and oil are "immiscible", meaning they do not mix but stay separated when combined in a glass. What is the best explanation for this?

1.both are polar molecules

2.both are nonpolar molecules

3.water is a polar molecule and oil is a nonpolar molecule

4.water and oil are both compounds

Theoretically, which metal should be the most reactive? hydrogen lithium francium fluorine

1)each group 16 element has how many valence electrons? ( )4 ( )6 ( )8 ( )16 2)how many dots appear in the dot structure for calcium ion, ca2+? ( )zero ( )one ( )two ( )eight 3) which of the following atoms forms a cation to obtain an octet of outer shell electrons? ( )magnesium ( )oxygen ( )fluorine ( )helium 4) an al3+ ion contains 13 protons and 10 electrons. ( )true ( )false 5) valence and non-valence electrons are represented in lewis dot structures. ( )true ( )false

As changes in energy levels of electrons increase, the frequencies of atomic line spectra they emit