Specify why the noble gases were among the last naturally occurring elements to be discovered.

The noble gases include helium, neon, argon, krypton, radon and xenon. Identify the time period when most of the noble gases were discovered.

Which of the following is the first noble gas?AXenonBHeliumCKryptonDRadon

The elements in Group 18 are known as noble gases.In terms of their electron configurations, explain what the noble gases all have in common.

Dmitri Mendeleev is credited with grouping the elements by atomic mass and observing that similar properties emerge periodically.  Henry Moseley then determined that a fundamental property, which Ernest Rutherford later called the atomic number, is more important than atomic mass for ordering the elements.As the periodic table took shape, scientists noted certain properties and trends.  For example, Rayleigh and Ramsay observed that some elements are unreactive and gave them the name noble gases.  But it was not until Niels Bohr described his model of the atom that scientists understood why noble gases are stable.Another important trend was discovered by Linus Pauling.  He was the first to identify electronegativity as a way to describe bonds that are neither completely ionic nor completely covalent.  Pauling assigned fluorine the highest electronegativity value of 4.0 because of its strong tendency to attract electrons when bonded to other atoms.  All other atoms were assigned values relative to fluorine.  This became known as the Pauling electronegativity scale.Scientists identified other trends based on x-ray crystallography and reactivity studies.  Figure 1 shows the first ionization energy of the elements, and Figure 2 shows electron affinity.Figure 1  First ionization energy of elementsFigure 2  Electron affinity of several elements (larger negative values indicate greater electron affinity) Question 35According to the information in the passage, in general, adding electrons to nonmetals is:A.not possible for most nonmetals.B.energetically similar to adding electrons to metals.C.easier than adding electrons to metals.D.more difficult than adding electrons to metals.

44. Which statement does not describe noble gases?1 pointThe more massive noble gases react with other elements.They belong to group VIIIA or 18.They contain at least one metalloid.He, Ne, Ar, Kr, Xe and Rn are included in the group.