Lead-202 has a half-life of 53,000 years. How long will it take for 15/16 of a sample of lead-202 to decay? 106,000 years
159,000 years
212,000 years
265,000 years
(Thank you very much :L)

(01.02 mc) nicole pushes her bike up a hill. overhead, the sun exerts a gravitational force on earth. which statement is true about the bike and earth? they both experience contact forces. they both experience non-contact forces. the bike experiences a non-contact force and earth experiences a contact force. the bike experiences a contact force and earth experiences a non-contact force. they both experience non-contact forces.

Which of the following is not a transverse wave? a) soundb) lightc) radiod) all of thesee) none of these

What sort of waves exhibit the doppler effect?