Which of the following is not a characteristic of a hydrogen bond? 1. it is responsible for the unusual physical properties of water. 2. it is weaker than a covalent bond. 3. it is stronger than other dipole-dipole interactions. 4. it can occur when hydrogen is covalently bound to very electronegative elements liks f, cl, br and i.

Asample of silver (with work function ? = 4.52 ev) is exposed to an ultraviolet light source (? = 200 nm), which results in the ejection of photoelectrons. what changes will be observed if: silver is replaced with copper (? = 5.10 ev) more photoelectrons ejected no photoelectrons are emitted fewer photoelectrons ejected more energetic photoelectrons (on average) less energetic photoelectrons (on average)

Ageologist determines that a sample of a mineral can't be scratched by a steel nail but can be scratched by a masonry drill bit. based on this information, the sample mineral has to be softer than a. orthoclase. b. fluorite. c. apatite. d. corundum.

How many molecules are in 6.0 moles of methane