Answer:
D. 4
Explanation:
Reflection can be defined as a phenomenon which typically involves a change in the direction of a ray of light or waves as it falls on a smooth surface.
Simply stated, reflection occurs when a ray of light or wavefronts bounces off a smooth surface.
Hence, from the diagram provided above, the thin beam of light which illustrates reflection is the fourth because as it hit the surface, it bounced back to the medium from which it was originally propagated with.
El número de electrones en uno átomo es igual al número de protones. El número de neutrones es el diferencia entre el número másico del átomo y el número atómico. Usted debe aprender esta fórmula en caso de que sea en un examen o una prueba. ¡Puedes hacerlo!
Answer:
a. Rate constant: 1.2118x10⁻⁴ yrs⁻¹
b. The age of the object is 20750 years
Explanation:
a. We can solve the rate constant in an isotope decay by using Half-Life, as follows:
K = Ln 2 / Half-life
K = ln 2 / 5720 years =
<h3>1.2118x10⁻⁴ yrs⁻¹</h3><h3 />
b. The general equation of isotope decay is:
Ln [A] = -kt + Ln [A]₀
<em>Where [A] is concentration of the isotope after time t, </em>
<em>k is rate constant</em>
<em>and [A]₀ initial concentration of the isotope.</em>
<em />
Computing the values of the problem:
Ln [0.89x10⁻¹⁴] = -1.2118x10⁻⁴ yrs⁻¹t + Ln [1.1x10⁻¹³]
-2.5144 = -1.2118x10⁻⁴ yrs⁻¹t
20750 years = t
The age of the object is 20750 years
<em />
Answer:
Test for sulphate ion present in a given salt: Add barium chloride solution. If white precipitate is formed, presence of SO42- ion is confirmed.
Explanation:
Answer:
71 Ga has a naturally abundance of 36%
Explanation:
Step 1: Given data
Gallium has 2 naturally occurring isotopes: this means the abundance of the 2 isotopes together is 100 %. The atomic weight of Ga is 69.72 amu. This is the average of all the isotopes.
Since the average mass of 69.72 is closer to the mass of 69 Ga, this means 69 Ga will be more present than 71 Ga
Percentage 69 Ga> Percentage 71 Ga
<u>Step 2:</u> Calculate the abundance %
⇒Percentage of 71 Ga = X %
⇒Percentage of 69 Ga = 100 % - X %
The mass balance equation will be:
100*69.72 = x * 71 + (100 - x)*69
6972 = 71x + 6900 -69x
72 = 2x
x = 36 %
71 Ga has a naturally abundance of 36%
69 Ga has a naturally abundance of 64%