1. Which is more polar—a sulfur–bromine bond ( ) or a selenium–chlorine bond ( )? 2. True or false: The greater the nuclear charge of an atom, the greater its electronegativity. Explain. 3. Water, ,...

1. Which is more polar—a sulfur–bromine bond () or a selenium–chlorine bond ()?

2. True or false: The greater the nuclear charge of an atom, the greater its electronegativity. Explain.

3. Water,
, and methane,
, have about the same mass and differ by only one type of atom. Why is the boiling point of water so much higher than that of methane?