Atomic symbol: Tl
Atomic number: 81
Atomic mass: 204.38
Appearance: Silvery white solid at 25°C
Series: Post-transition metals
Electron configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹⁴ 5d¹⁰ 6s² 6p¹
Soft and malleable, can be easily cut with a knife.
Appearance is similar to lead.
Fun Fact! Some thallium compounds, like thallium sulfate and thallium hydroxide, are highly toxic. These compounds are used in rat poisons and insecticides.