Ytterbium

Ytterbium is atom number 70 — every Ytterbium atom has exactly 70 protons in its center, and that number is what makes it Ytterbium and nothing else. Its symbol is Yb. At room temperature it is a solid.

Ytterbium is a chemical element with symbol Yb and atomic number 70. It is the fourteenth and penultimate element in the lanthanide series, which is the basis of the relative stability of its +2 oxidation state. However, like the other lanthanides, its most common oxidation state is +3, seen in its oxide, halides and other compounds.

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

Ytterbium sits in period 6, group 3 of the f-block. Its 70 electrons fill shells of 2, 8, 18, 32, 8, 2 — written as [Xe] 4f14 6s2. Its electronegativity is 1.1 on the Pauling scale, and pulling the first electron off takes 603.4 kJ/mol. The outermost shell holds 2 electrons — the ones that do all the chemistry.

Full configuration: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14
Ionization energies (kJ/mol): 603.4, 1174.8, 2417, 4203
Electron affinity: -1.93 kJ/mol · Electronegativity (Pauling): 1.1
Density: 6.9 g/cm³ · melts 1097 K · boils 1469 K

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