To cut this short and for your understanding, ionic bond is formed between metals (mostly right column in periodic table). Covalent bond is formed between non-metals (mostly left column in periodic table). So polar covalent is also a covalent bond but it is polar, which means the shape of molecules are not symmetrical hence maybe an atom in a molecule has most of the electron attracted to it causing itself to be partial negative (since electron are negatively charged) and the other atom has its electron being attracted by others became partial positive. Polar covalent can also be when H atom is binding either to F, O or N (also known as hydrogen bond).
Answer:
Explanation:
The electron in the lowest energy state will be found in 1 s energy level.
set of 4 possible quantum numbers
Principal quantum no : n = 1 ,
Azimuthal quantum no l = 0
Magnetic quantum no m = 0
Spin quantum no s = + 1/2
set of other quantum nos
Principal quantum no : n = 1 ,
Azimuthal quantum no l = 0
Magnetic quantum no m = 0
Spin quantum no s = - 1/2