Sr

Ca

Ba

Mg

Fe

Si

Na

      99.5%min

     0.2%max

    0.1%max

    0.05%max

   0.05%max

    0.02%max

   0.05%max

99%min

0.3%max

0.3%max

0.1%max

0.05%max

0.02%max

0.1%max

Packing: packed in aluminium jar, 2.5kg/ a jar, then in iron drum with double-decked plastic bag full of argon gas, 50kg/drum

General

Name, Symbol, Number

strontium, Sr, 38

Element category

alkaline earth metals

Group, Period, Block

2, 5, s

Appearance

silvery white metallic

Standard atomic weight

87.62(1)  g·mol−1

Electron configuration

[Kr] 5s2

Electrons per shell

2, 8, 18, 8, 2

Physical properties

Phase

solid

Density (near r.t.)

2.64  g·cm−3

Liquid density at m.p.

2.375  g·cm−3

Melting point

1050 K
(777 ℃, 1431 F)

Boiling point

1655 K
(1382 ℃, 2520 F)

Heat of fusion

7.43  kJ·mol−1

Heat of vaporization

136.9  kJ·mol−1

Specific heat capacity

(25 ℃) 26.4  J·mol−1·K−1

Atomic properties

Crystal structure

cubic face centered

Oxidation states

2, 1[1]
(strongly basic oxide)

Electronegativity

0.95 (Pauling scale)

Ionization energies
(more)

1st:  549.5  kJ·mol−1

2nd:  1064.2  kJ·mol−1

3rd:  4138  kJ·mol−1

Atomic radius

200  pm

Atomic radius (calc.)

219  pm

Covalent radius

192  pm

Miscellaneous

Magnetic ordering

paramagnetic

Electrical resistivity

(20 ℃) 132 n Ω·m

Thermal conductivity

(300 K) 35.4  W·m−1·K−1

Thermal expansion

(25 ℃) 22.5  µm·m−1·K−1

Shear modulus

6.1  GPa

Poisson ratio

0.28

Mohs hardness

1.5

CAS registry number

7440-24-6

Most-stable isotopes