Arsenic

Arsenic is atom number 33 — every Arsenic atom has exactly 33 protons in its center, and that number is what makes it Arsenic and nothing else. Its symbol is As. At room temperature it is a solid.

Arsenic is a chemical element with symbol As and atomic number 33. Arsenic occurs in many minerals, usually in conjunction with sulfur and metals, and also as a pure elemental crystal. Arsenic is a metalloid.

Summary from the source dataset, derived from Wikipedia (CC BY-SA 3.0) · original article

Arsenic sits in period 4, group 15 of the p-block. Its 33 electrons fill shells of 2, 8, 18, 5 — written as [Ar] 3d10 4s2 4p3. Its electronegativity is 2.18 on the Pauling scale, and pulling the first electron off takes 947 kJ/mol. The outermost shell holds 5 electrons — the ones that do all the chemistry.

Full configuration: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p3
Ionization energies (kJ/mol): 947, 1798, 2735, 4837, 6043, 12310
Electron affinity: 77.65 kJ/mol · Electronegativity (Pauling): 2.18
Density: 5.727 g/cm³ · melts — · boils —

Values exactly as published — see where the data comes from.