An element has a half-life of 50 years. If a rock contains 1/16 of the parent element and 15/16 of the daughter element how many half lives have passed and how old is the rock

2. which of the following statements does not accurately describe stem cells? a. embryonic stem cells make up the inner cell mass of a blastocyst. b. with more research, stem cells may be used to repair or replace damaged cells. c. the use of stem cells is without any objections since it can be used in therapies to humans. d. adult stem cells are multipotent and can differentiate into many types of cells.