22.8 gms
Step-by-step explanation:
Step 1:
Given,
Mass of the element = 590 gms
Percentage decay per minute = 19.5%
Step 2 :
Fraction of the element remaining at the end of 1 minute = 1 - 0.195 = 0.805
Hence the fraction of element remaining after 15 minutes = = 0.03863
So the mass of the element remaining after 15 minutes = 0.03863 * 590 = 22.8 rounded off to the nearest 10th of a gram
mass of the element remaining after 15 minutes = 22.8 gms