Answer is: lithium.
Electronegativity (χ) is a property that describes the tendency of an atom to attract a shared pair of electrons.
Electronegativity increases from left to right across a period.
Atoms with higher electronegativity attracts more electrons towards it, electrons are closer to that atom.
For example nitrogen has electronegativity approximately χ = 3 and lithium has χ = 1, so if they form bond, nitrogen will have negative and lithium positive charge.