Stable isotope Francium (Fr)

 
Isotope Atomic Mass Half-life Mode of Decay Nuclear Spin
Fr-210 209.99640 3.20 minutes α to At-206; EC to Rn-210 6
Fr -211 210.99553 3.10 minutes α to At-207; EC to Rn-211 9/2
Fr-212 211.99618 20 minutes α to At-208; EC to Rn-212 5
Fr-213 212.99617 34.60 seconds α to At-209; EC to Rn-213 9/2
Fr-214 213.99895 0.0051 seconds α to At-210 1
Fr-215 215.00033 0.0000012 seconds α to At-211 9/2
Fr-216 216.00319 0.000007 seconds α to At-212; EC to Rn-216 No data available
Fr-217 217.00462 0.00016 seconds α to At-213 9/2
Fr-218 218.00756 0.001 seconds α to At-214 1
Fr-219 219.00924 0.021 seconds α to At-215 9/2
Fr-220 220.01231 27.40 seconds α to At-216; β- to Ra-220 1
Fr-221 221.01425 4.80 minutes α to At-217; β- to Ra-221; C-14 5/2
Fr-222 222.01754 14.30 minutes β- to Ra-222 2
Fr-223 223.019733 22 minutes α to At-219; β- to Ra-223 3/2
Fr-224 224.02323 3 minutes β- to Ra-224 1
Fr-225 225.02561 3.90 minutes β- to Ra-225 3/2
Fr-226 226.0293 49 seconds β- to Ra-226 1
Fr-227 227.0318 2.48 minutes β- to Ra-227 1/2

Properties of Francium

Name Francium
Symbol Fr
Atomic number 87
Atomic weight 223
Standard state Solid at 298 °K
CAS Registry ID 7440-73-5
Group in periodic table 1
Group name Alkali metal
Period in periodic table 7
Block in periodic table s-block
Color Metallic
Classification Metallic
Melting point 30 °C
Boiling point 598 °C
Thermal conductivity 15 (estimate) W/(m·K)
Electronegativity 0.7
Heat of vaporization About 65 kJ·mol-1
Heat of fusion About 2 kJ·mol-1
Density of solid 2.9 (estimated) g/cm3
Electron configuration [Rn]7s1 
Oxidation state +1