Iodine-131 is a radioactive isotope that is used as a medical tracer to study and treat the thyroid gland. this radioactive element emits both beta particles and gamma waves. to effectively stop both beta particles and gamma waves, scientists use a chamber composed of

a) concrete.
b) lead.
c) metal.
d) plastic.

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)

Which diagram shows the correct way to represent an ionic compound of magnesium oxide?

Draw the structure for 5-isopropyl-2-methyl-3-nonene