If 250 mg of a radioactive element decays to 190 mg in 24 hours, find the half-life of the element. (round your answer to the nearest whole number.)

61 hours

Explanation:

In this question we will use radioactive decay model

m0= 250 mg

h is the hlf life of element

m(t) is the mass left after t time

so,

solving this equation for h

reaaranging and taking ln on both the sides we get

solving further we get

h= 60.62 hours ≅61 hour

the half life of element is 61 hours

calculate how many grams of ammonia can be produced from 4.21 grams of

n2 + 3h2 = 2nh3

my answer:

25.0g n2 x (1 mol/ 28.0gn2) x (2 mol nh3/ 1 mol n2) x (17.0g nh3/ 1 molnh3) = 30.36g n2

25.0g h2 x (1 mol h2/ 2.00g h2) x (2 mol nh3/ 3 mol h2) x (17.0g nh3/ 1 mol nh3) = 141.67g h2

lr = n2

your parents i think this could be it