Answer:
15 h
Explanation:
Okay, the first thing that we all have to know before we can answer this question is that this Topic that is, Chemistry of Radioactivity is related to kinetics in a way that Radioactive disintegration follows the first order of Reaction which is under kinetics. So, we will be using the first order kinetics rate law to answer this question. Using the equation (1) below;
k =[ 2.303/ t ]×log ([N°}/ [Nr]) --------(1).
We are given from the question that N° = initial sample = 0.8 mg and Nr= sample remaining = 0.2 and the time taken = t= 30.0 h.
k= (2.303/ 30.0 h ) × log (0.8/0.2).
k=0.076768 h^-1 × log (4).
k= 0.076768 h^-1 × 0.6021.
k= 0.0462 h^-1.
Therefore, using the formula for Calculating half life below for first order kinetics we will be able to find out answer.
k = ln 2/ t(1/2). Where t(1/2) is the half life.
t(1/2) = ln 2/ k.
t(1/2) = ln 2 / 0.0462 h^-1.
t(1/2)= 0.6931/0.0462 h^-1.
t(1/2)=15 h
Nal is the sodium iodide
The oxidation number of sodium in sodium iodide is 1.<span>Formula: NaIHill system formula: I1Na1CAS registry number: [7681-82-5]Formula weight: 149.894Class: iodideColour: whiteAppearance: crystalline solidMelting point: 660°CBoiling point: 1304°CDensity: 3670 °C</span>
<span>The strong bonds give graphite high boiling and melting points, while the weak bonds make graphite soft and flexible.</span>
Given are the steps in the titration process:
- Clean and rinse the burette with water
- Read and record the initial burette volume.
- Fill the burette with standardized base solution
- Rinse the burette with standardized base solution
The steps in the titration process is as follows:
1.) Clean and rinse the burette with water
2.) Rinse the burette with standardized base solution
3.) Fill the burette with standardized base solution
4.) Read and record the initial burette volume
Answer:b
Explanation: the particles will soon dissolve which means that the particles are changing but the volume is staying the same and the concentration is changing