Answer:
hope this helps
Step-by-step explanation:
a. 1/4 as a power of 2 = root 4 v/2
b.
Radium-226 mass decays to 1/4 of it mass every 6400 years
64gr ( 1/4) = 16gr ----→after 6400 years its mass is 16gr
now its current mass is 16gr
16gr (1/4) = 4gr -----> after another 6400 years its mass is 4gr
again, its current mass after 12800 years is 4gr
4gr (1/4) = 1gr ------> after another 6400 years its mass is 1gr
why 4600 3 times? = 4600+4600+4600 = 19200 years
the remaining mass after 19200 years is 1gr
