How many valence electrons does strontium have?

The periodic table of the elements online

84Sr (strontium-84)

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Nuclide properties

Basic properties Mass number: 84 Number of neutrons: 46 Number of protons: 38 Energy level: 0 MeV Spin: 0    Mass and Energy: Atomic mass: 83.91342532 u Core mass: 83.89257928 u Mass excess: -80.6438 MeV Binding energy (total): 728.906 MeV Binding energy (per u): 8,677 MeV    
Occurrence and distribution:Share in the isotope mixture*: 5600 mg / kgShare universe:0.224 µg / kgShare of sun:0.28 µg / kgShare of earth envelope:0.784 mg / kgShare of earth's crust:2,072 mg / kg_______________
*Share in the natural isotope mixture of the isolable, stable or very long-lived element. The composition of the isotope mixture is stable within narrow limits for any location of the element.
Effective cross-sections:   σ (n, γ)0.199 barn  σ (n, it)0.623 barn  
swell for the mass defects and half-lives: http://www.nndc.bnl.gov/chart/. The Atomic masses correspond to the mass numbers in u minus the proportional mass defect. Core masses corresponds to atomic masses less the electron masses, whereby the binding energy of the electrons Not taken into account so that they deviate from the actual value by a few eV! The Half-lives are also literature values ​​from the named source. All other information (service life, decay constant) is calculated from them. The Decay energies are calculated from the differences in the masses of the particles involved in the decay; it is also done automatically by a script.