1) Carbon-13:
Proton-6 Neutron-7 Electron-6
2)Atomic mass of element X:
(55*10+56*20+57*70)/100=56.6
The model that should show the corresct representation of xenon gas is one in which the gas molecules are isolated and monoatomic.
<h3>What is a noble gas?</h3>
A noble gas is a member of group 18 of the periodic table. Noble gases are known not to interact with each other and occur as monoatomic particles.
The images are not shown here hence the question is incomplete. However, we do know that any of the models that show individual monoatomic particles is a representation of xenon gas.
Learn more about noble gas: brainly.com/question/2094768
Cadium
Down a period, atomic radii decrease from left to right due to the increase in the number of protons and electrons across a period.
<span>Water molecules form a complex with metal ions (usually a 6-coordinate complex). And the high charge density on a metal ion draws electrons away from the water molecules, making the O-H bonds more polar than normal. This allows the dissociation of the protons, making solutions of most metal ions acidic</span>