Answer:
Average atomic mass of uranium= 237.98 amu.
Explanation:
Given data:
Abundance of U²³⁴ = 0.01%
Abundance of U²³⁵ = 0.17%
Abundance of U²³⁸ = 99.28%
Average atomic mass = ?
Solution:
Average atomic mass of uranium = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass) +(abundance of 3rd isotope × its atomic mass) / 100
Average atomic mass of uranium= (234×0.01)+(235×0.71)+(238×99.28)/100
Average atomic mass of uranium= 2.34 + 166.85 + 23628.64 / 100
Average atomic mass of uranium= 23797.83 / 100
Average atomic mass of uranium= 237.98 amu.
Explanation:
(1) When a proton is converted into neutron then the positron emission takes place as follows.
A positron is represented by the symbol . Therefore, when a positron emission occurs then the resultant nuclei atomic number decreases by a unit mass.
General equation representing positron emission is as follows.
Hence, Fluorine-18 decays by positron emission as follows.
Therefore, when 18F undergoes positron emission, the product nucleus is, .
(2) Expression for the half-life of a isotope is as follows.
Initial activity, () = 4.00 millicuries
Activity after 95% =
= 0.20 millicuries
t = 7.912 hrs
Thus, we can conclude that it will take 7.91 hrs for 95% of the 18F to decay.
Sodium hydrogen carbonate is a weak base because it is not a water soluble hydroxide.
Answer:
Below:
Explanation:
The Contact process If the temperature is increased, the equilibrium position moves in the direction of the endothermic reaction. This means it moves to the left in the Contact process. ... However, the rate of reaction is low at low temperatures. So, as in the Haber process, a compromise temperature of 450 °C is chosen.
Habar Process...
The Haber process, also called the Haber–Bosch process, is an artificial nitrogen fixation process and is the main industrial procedure for the production of ammonia today. It is named after its inventors, the German chemists Fritz Haber and Carl Bosch, who developed it in the first decade of the 20th century.
Hope it helps..,
It’s Muska...ʕ•ᴥ•ʔ
Chemical reactions are ultimately the reconfiguration of reactants to form products that are in a more energetically favourable state. In this sense, the vast majority of chemical reactions have reactants and products that are at different energy levels.
This means that energy either has to enter or leave the chemical compounds. Some of this energy is in the form of heat, which will cause the system to cool down or heat up.
So, detecting a change in temperature is a good way to find out if a chemical reaction has occurred. Of course, chemical reactions can occur with no detectable change in temperature, and a change in temperature does not necessarily confirm a chemical reaction has occurred.