The half-life of an element is 10 years. How much of a 20g sample will remain after 50 years?
Choices: 0.625g , 1.25g , 2.5g, 5g
my answer is 2.5g.
considering: 20g is a half life an element. since it is 50 yrs... then there are five 10 years in a 50 years. so in every 10 years there corresponds half life
5 time half life = 5 x 1/2 = 2.5 ...
please help me understand the problem. and hope somebody will correct or check my work. because im not sure of my answer