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Chem Studio by Learn4Less

Element 20

Calcium (Ca)

20
Ca

calcium

Metal · s block · group 2, period 4

Electron configuration
[Ar] 4s2[\mathrm{Ar}]\,4s^{2}
Unpaired electrons
0 (diamagnetic)
Valence electrons
2
Molar mass
40.078 g/mol
Electronegativity
1
Atomic radius
197 pm
First ionization energy
590 kJ/mol
Next ionization energies
1,145, 4,912, 6,491
Electron affinity
2 kJ/mol released

Practice

Practice calcium

Questions from the course about calcium. If you’re signed in, your answers count toward your progress.

  1. Question 1Photoelectric effect: kinetic energy of ejected electronsExam level

    Light of wavelength 286 nm286\ \mathrm{nm} shines on a clean calcium surface. The work function of calcium is ϕ=2.87 eV\phi = 2.87\ \mathrm{eV} (1 eV=1.602×10−19 J1\ \mathrm{eV} = 1.602 \times 10^{-19}\ \mathrm{J}). What is the maximum kinetic energy of the ejected electrons, in J?

    J\mathrm{J}

    Scientific notation: type 4.86e-7 or 4.86 x 10^-7.

  2. Question 2Ground-state electron configurationWarm-up

    Which is the ground-state electron configuration of a neutral calcium atom (Ca\ce{Ca})?

  3. Question 3Electron configuration of an ionWarm-up

    Which is the ground-state electron configuration of CaX2+\ce{Ca^2+}?