How does the arrangement of the main group elements reflect the patterns of outermost electrons?

Which is the layer underground where all empty spaces are filled with a combination of air and water ?

Which of the following signs of a chemical reaction are observed in the reaction of potassium with water? precipitate formed temperature change smell produced gas produced color change

What type of interaction occurs between the r groups of valine and isoleucine in a tertiary structure? view available hint(s) what type of interaction occurs between the r groups of valine and isoleucine in a tertiary structure? salt bridge disulfide bridge hydrogen bond hydrophobic interaction