The amount of substance present in a certain object with a given half-life in terms of h can be expressed through the equation,
A(t) = (A(o))(0.5)^(t/h)
where A(t) is the amount of substance after t years and A(o) is the original amount. In this item we are given that A(t)/A(o) is equal to 0.89. Substituting the known values,
0.89 = (0.5)(t / 5730 years)
The value of t from the equation is 963.34 years.
<em>Answer: 963 years</em>
Answer:
The answer to your question is d. 0.5 M
Explanation:
Data
[A] = 1M
K = 0.5
Concentration of B and C at equilibrium = x
Concentration of A at equilibrium = 1 - x
Equation of equilibrium
k = ![\frac{[B][C]}{A}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BB%5D%5BC%5D%7D%7BA%7D)
Substitution
![0.5 = \frac{[x][x]}{1 - x}](https://tex.z-dn.net/?f=0.5%20%3D%20%5Cfrac%7B%5Bx%5D%5Bx%5D%7D%7B1%20-%20x%7D)
Simplification
0.5 = 
Solve for x
0.5(1 - x) = x²
0.5 - 0.5x = x²
x² + 0.5x - 0.5 = 0
Find the roots x₁ = 0.5 x₂ = -1
There are no negative concentrations so the concentration of A at equilibrium is
[A] = 1 - 0.5
= 0.5 M
It will most likely get flooded at one point in time.
Answer:
56160grams
Explanation:
First, we need to convert the number of molecules of magnesium chloride (MgCl2) into moles by dividing by Avagadro's number (6.02 × 10^23 molecules)
n = nA ÷ 6.02 × 10^23
n = 14.07 × 10^26 ÷ 6.02 × 10^23
n = 14.07/6.02 × 10^(26-23)
n = 2.34 × 10^3 moles of MgCl2
The balanced reaction given in the question is as follows:
Mg + 2HCl → MgCl2 + H2
If 1 mole of Mg produced 1 mole of MgCl2
Then, 2.34 × 10^3 moles of Mg will also produce 2.34 × 10^3 moles of MgCl2.
Using mole = mass ÷ molar mass (MM)
Molar mass of Mg = 24g/mol
mass = mole × MM
mass = 2.34 × 10^3 × 24
mass = 56.16 × 10^3
mass = 56160grams.
Answer:
To find the noble gas notation, you first take the noble gas before the element you’re trying to find the notation for. In this case, the noble gas before Calcium is Argon. You put the symbol for Argon in square brackets, and then you write out the rest of the notation as you would normally.
This would look like [Ar]4s^2
The 4s^2 is because Calcium is the second element in the 4s columns (refer to the diagram)
Hope this helps :)
