What does sodium form an ion a+1 charge

It has only 1 electron in its valence shell and if that electron is removed it will acquire noble gas configuration

Explanation:

Sodium forms an ion of charge +1 as in its ionic state it has inert gas configuration

It forms an ion of charge +1 when the valence shell electron is removed to gain the noble gas configuration and the electrons can be removed mostly from its valence shell because inner shell electrons will be tightly bounded to the nucleus of the atom and it requires high energy to remove the electron present in the inner shell when compared to the valence shell (outermost shell)

a high pressure system is a dense air mass that is usually cooler and drier than the surrounding air. a low pressure system is a less dense air mass that is usually wetter and warmer than the surrounding air.

in general, areas that experience high atmospheric pressure also experience fair weather. low pressure systems can cause the formation of clouds and storms. air usually flows from areas of high pressure to areas of low pressure..

i think the answer is a, hope this is right, that would be my best guess.