Question 4 of 20
4 Points
A radioactive element has a half-life of 3,000 years. If a sample of this
element begins with a mass of 60 grams, how long would you have to wait for
the mass to decrease to 15 grams?
O
A. 6,000 years
O
B. 12,000 years
O
O
C. 3,000 years
D. 1,500 years
BH

You have been tasked with sorting the rock samples shown into three categories, with two rocks in each category. what attribute would you use to sort these rocks? which rocks would be in each category? rocks: obsidian, coquina limestone, granite, soapstone,pumice, and gneiss.