is cesium neutral if so how many electrons does it have
If by neutral you mean a charge of zero, a cesium atom is neutral. The number of positive charges in the atom is equal to the number of protons that is equal to its atomic number or 55. The atom also has 55 electrons which are negatively charged and the protons and electrons make the Cesium atom electrically neutral.
Considering the reactivity of cesium, the element is not inert cesium is an alkali metal and has one electron in its electron shell more than the stable electron configuration of the nearest noble gas. To achieve this, the cesium atom reacts with other elements that can accept an electron. Once an electron has been donated, a positively charged cesium ion is formed that is not chemically reactive but forms chemical compounds with other negatively charged ions.