What quality do all of the elements in group 18, the noble gases, share?
1) They all have 8 valence elections
2) They all have the same number of protons in their nucleus.
3) They are all highly reactive.
4) They all have a full outer valence shell.
4) They all have a full outer valence shell.
The correct answer is option 4) They all have a full outer valence shell. Noble gases, which make up Group 18 of the periodic table, have a full complement of valence electrons in their outermost energy level. This makes them stable and less likely to react with other elements, hence the term "noble."
The correct answer is 4) They all have a full outer valence shell.
To explain how to arrive at this answer, let's break it down:
Group 18 in the periodic table is known as the noble gases. The noble gases include elements such as helium, neon, argon, krypton, xenon, and radon.
To determine the quality that all elements in group 18 share, we need to examine the characteristics of the noble gases.
Option 1) They all have 8 valence electrons:
This statement is not entirely accurate. While most elements strive to have a full outer valence shell of 8 electrons (known as the octet rule), in the case of the noble gases, this is not necessarily true. The noble gases have different numbers of valence electrons depending on their position in the periodic table.
Option 2) They all have the same number of protons in their nucleus:
This statement is incorrect as well. The number of protons in the nucleus determines the atomic number of an element, and for the noble gases, this number varies from helium with 2 protons to radon with 86 protons.
Option 3) They are all highly reactive:
This statement is incorrect. In fact, the noble gases are known for being chemically unreactive or inert. They rarely form compounds with other elements due to their stable electron configurations.
Option 4) They all have a full outer valence shell:
This statement is accurate. The one quality that all elements in group 18, the noble gases, share is having a full outer valence shell. Elements in this group, with the exception of helium, have 8 valence electrons in their outermost energy level, which satisfies the octet rule. This full outer shell configuration results in a high level of stability, reducing their tendency to bond with other elements.
Hence, the correct answer is 4) They all have a full outer valence shell.