Neutron capture reactions.
Isotopes of the same element have the same number of protons in each nucleus. However, their nucleus differ in the number of neutrons. Adding one or more neutrons to a nucleus will converts it to a different isotope of the same element.
Neutrons can be produced with a particle accelerator. The researcher might aim fast moving alpha particles from the accelerator at a beryllium Be target.
Doing so will convert beryllium-9 to carbon-12 and release one neutron.
The neutron produced in this process moves very fast ("fast neutrons"). It might knock protons or alpha particles off the target nucleus. This is undesirable since the nucleus will have a change in its proton number. It will end up belonging to a different element.
The researcher should reduce the speed of those neutrons. Passing neutrons through moderators greatly reduces their speed. Moderators are materials that are rich in light nuclei. They remove the energy of neutrons as the two collide. Examples of moderators are heavy water (D₂O) and graphite (carbon). Slow neutrons are easier to capture than fast-moving ones. Combining those slow-moving neutrons to the source isotope will likely produce a different isotope of the same element.
Vitz, Ed. et. al, "19.5: Neutron Bombardment", ChemPRIME (Moore et al.), Libretexts Chemistry, 2017
Answer:
D. BY ADDING OR REMOVING NEUTRONS.
Hope this helps!
Explanation:
Answer:
2
Explanation:
Pure water is not a mixture....it is only water
gold ...is only gold
2. air IS a mixture of various gases.....nitrogen , oxygen, co2 etc
Option 2: The air in your room. The air in your room is an example of a mixture because it consists of various gases that can be separated from each other.
The correct answer is Option 2: The air in your room.
A mixture is a combination of two or more substances that are not chemically bonded together. The air in your room is a mixture because it consists of various gases such as oxygen, nitrogen, carbon dioxide, and others. Each gas retains its individual properties and can be separated from the others.
On the other hand, pure water is a compound because it consists of two hydrogen atoms bonded to an oxygen atom, while gold is an element because it is composed of only gold atoms.
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Answer : The temperature on the kelvin scale is, 277.15 Kelvin
Explanation :
As we are given the temperature in degree Celsius. Now we have to need to convert the temperature from degree Celsius into kelvin.
Conversion used for the temperature from degree Celsius to Kelvin :
Therefore, the temperature on the kelvin scale is, 277.15 Kelvin
(2) lead (Pb) (4) chlorine (Cl)
Answer: Option (1) and (2) are correct.
Explanation:
Elements which contain same number of valence electrons tend to show similar chemical properties. This is because having same number of valence electrons will make the atoms to react in a similar way.
For example, Silicon is a group 14 element. So, it contains only 4 valence electrons. Similarly, germanium and lead are group 14 elements and it has 4 valence electrons.
Therefore, silicon, germanium, and lead will have similar chemical properties.
Whereas phosphorous is a group 15 element, and chlorine is a group 17 element.
Thus, we can conclude that out of the given options germanium and lead elements has physical and chemical properties most similar to silicon (Si).
B. 6
C. 2
D. 10
Answer : The correct option is, (A) 8
Explanation :
Octet rule : It is the tendency of atoms to have eight electrons in the valence shell. When the atoms have fewer than eight electrons then they tend to react and form the more stable compounds.
Or we can say that the atoms attempt to get a noble gas electron configuration, which is eight valence electrons.
For example : As we know that the sodium has one valence electron, so if giving it up then the result in the same electron configuration as the neon and chlorine has seven valence electrons, so if it takes one it will have eight and the result in the same electronic configuration as the argon.
Hence, the correct option is, (A) 8