The number of hours required : 37.2 hours
<h3>Further explanation</h3>
Given
⁴²K (potassium -42)
Required
The number of hours
Solution
The atomic nucleus can experience decay into 2 particles or more due to the instability of its atomic nucleus.
Usually, radioactive elements have an unstable atomic nucleus.
Based on Table N(attached), the half-life for ⁴²K is 12.4 hours, which means half of a sample of ⁴²K will decay in 12.4 hours
For three half-life periods :

Answer:
133.3atm
Explanation:
Given parameters:
Initial volume = 400ft³
Final volume = 3ft³
Initial pressure = 1atm
Unknown:
Final pressure = ?
Solution:
To solve this problem, we apply Boyle's law which states that "the volume of a fixed mass of a gas varies inversely as the pressure changes if the temperature is constant".
Mathematically;
P₁V₁ = P₂V₂
P and V are pressure and volume
1 and 2 are initial and final states;
Insert parameters and solve;
1 x 400 = P₂ x 3
P₂ = 133.3atm
Answer:
6 orbitals
Explanation:
An atom of mercury will have 6 - orbitals because it can be found on the 6-period in the periodic table of elements.
Orbitals or shells are energy levels in which electrons are placed within an atom.
Let us write the shell notation of the element:
Hg has 80 electrons:
K L M N O P
2 8 18 32 18 2
So, we have six orbitals
Kinetic energy of an object can be expressed in terms of its mass m and velocity v as:
KE = 1/2 * m* v²
Thus higher the velocity, greater will be the Kinetic energy. Now, as the box moves along a ramp from top to bottom, its velocity increases and so does the KE. Hence, kinetic energy is maximum at the bottom
Ans B) at the bottom
Answer:
pH = 5.58
Explanation:
Given that :
Citric acid is a triprotic acid with the formula
. Tripotic acids are acids that have the tendency to yield three protons per molecule during the phases of dissociation, therefore they have three pka.
For Citric acid; the pka values are:

So, the pH of sodiummonohydrogencitrate with the chemical formula
which can act as an acid and a base (i.e it is said to be amphoteric) can be calculated as :


pH = 5.58
Therefore, the approximate pH of a solution of sodium monohydrogencitrate = 5.58