Answer:
The correct answer is - 800.
Explanation:
Given:
Total amount = ? or assume x
spend in buying birthday item = 3/4 of x
given to sister = 1/5 of x
remaining to mother = 40
solution:
the remaning amount = x- (3x/4+x/5) = 4=
=> x- 19x/20 = 40
=> x = 20*40
=> x = 800
thus, the correct answer is = 800
The general equation for radioactive decay is;
N = N₀e^(-λt)
x - decay constant (λ) - rate of decay
t- time
N - amount remaining after t days , since we are calculating the half life, amount of time it takes for the substance to to be half its original value, its N₀/2
N₀ - amount initially present
substituting the values
N₀/2 = N₀e^(-0.081t)
0.5 = e^(-0.081t)
ln (0.5) = -0.081t
-0.693 = -0.081t
t = 0.693 / 0.081
= 8.55
half life of substance is 8.55 days
Here’s the math for your answer, which is 3.3 L HCl
Answer:

Explanation:
Hello!
In this case, since the molarity is defined as moles of solute divided by liters of solution, since we have phenol with a molar mass of 94.12 g/mol, we can first compute the moles in 1.5 g of phenol:

Next, since 1000 mL = 1 L, we notice that the volume of the solution is 0.100 L and therefore, the molarity of such solution turns out:

Best regards!
The period is the end of the sentence!!!