Convert 1 3/5 to an improper fraction;
-1 × 5 + 3/5 ÷ -2/3
Simplify 1 × 5 to 5
-5 + 3/5 ÷ -2/3
Simplify 5 + 3 to 8
-8/5 ÷ -2/3
Use this rule: a ÷ b/c = a × c/b
-8/5 × 3/-2
Use this rule; a/b × c/d = ac/bd
-8 × 3/5 × - 2
Simplify 8 × 3 to 24
-24/5 × -2
Simplify 5 × -2 to -10
- 24/-10
Move the negative sing to the left
-(-24/10)
Simplify 24/10 to 12/5
-(-12/5)
Simplify brackets
12/5
Convert to a mixed fraction
<u>= 2 2/5</u>
26( w times w times w less than nvm its less than
The mass of substance left after 7 days is 13.09 g
The mass of substance left, N is given by
N = N₀exp(-λt) where λ = decay constant and N₀ = initial mass of substance present = 24 g and t = time
Also, λ = 0.693/t' where t' = half-life of iodine = 8 days
So, λ = 0.693/t'
λ = 0.693/8
λ = 0.086625/day
Since the mass of substance left is N = N₀exp(-λt) and we require the mass of substance after t = 7 days,
N = N₀exp(-λt)
N = 24 gexp(-0.086625/day × 7 days)
N = 24 gexp(-0.606375)
N = 24 g × 0.5453
N = 13.09 g
So, the mass of substance left after 7 days is 13.09 g
Learn more about radioactive decay here:
brainly.com/question/23705307
Expanding the digits, we have
