A34 gram sample of a substance that's used to treat thyroid disorders has a k-value of 0.137. find the substance's half-life, in days. round to the nearest tenths.

5.1 days

Step-by-step explanation:

Given in the question,

initial amount of substance = 34 grams

k-value = 0.137

To find the half life of this substance we will use following formula

here N(0) is initial amount of substance

        t is time in days

Plug values in the formula

1/2 = e^{-0.137t}

Take logarithm on both sides

ln(1/2) = ln( e^{-0.137t})

ln(1/2) = -0.137t

t = ln(1/2) / -0.137

t = 5.059

t ≈ 5.1 days (nearest to tenths)

51

step-by-step explanation:

73-22=51 the   mass number minus the amount of protons gives you the amount of neutrons

the system of inequalities is

step-by-step explanation:

step 1

find the equation of the dashed line

we have the points

(0,0) and (3,1)

the line passes through the origin, so, is a direct variation

find the slope

the equation of the dashed line is

the solution of the inequality a s the shaded area above the dashed line

therefore

the equation of the inequality a is

step 2

find the equation of the solid line

we have the points

(4,0) and (0,4)

find the slope

the equation of the solid line is

the solution of the inequality b s the shaded area below the solid line

therefore

the equation of the inequality b is

step 3

the system of inequalities is