Caesium

Caesium,  ₅₅Cs

ngoi-kôn
silvery gold Spectral lines of caesium
Kî-pún sin-sit
Miàng, fù-ho	caesium, Cs
phe̍t-miàng	cesium
ngoi-hìn	silvery gold
Caesium chhai chû-khì-péu ke vi-chi
Rb ↑ Cs ↓ Fr xenon ← caesium → barium
ngièn-chṳ́ sì-sú	55
ngièn-chṳ́-liòng (±)	132.90545196(6)
ngièn-su lui-phe̍t	kán-kîm-su̍k
Chhu̍k, fûn-khî	1 chhu̍k, s-block
chû-khì	period 6
thien-chṳ́ phài-lie̍t	[Xe] 6s1
per shell	2, 8, 18, 18, 8, 1
vu̍t-lî sin-chṳt
Siông	ku-thí
yùng-tiám	301.7 K ​(28.5 °C, ​83.3 °F)
pui-tiám	944 K ​(671 °C, ​1240 °F)
Me̍t-thu near Sit-vûn	1.93 g·cm−3
1.843 g·cm−3
lìm-kie-tiám	1938 K, 9.4 MPa
Yùng-fa-ngie̍t	2.09 kJ·mol−1
Chîn-fat-ngie̍t	63.9 kJ·mol−1
Ngie̍t-yùng-liong	32.210 J·mol−1·K−1
chîn-hi-ap P (Pa) 1 10 100 1 k 10 k 100 k chhai T (K) 418 469 534 623 750 940
Ngièn-chṳ́ sin-chṳt
Yông-fa-su	+1, −1 ​(a strongly basic oxide)
Thien-fu-sin	Pauling scale: 0.79
Thien-lì-nèn	1st: 375.7 kJ·mol−1 2nd: 2234.3 kJ·mol−1 3rd: 3400 kJ·mol−1
Ngièn-chṳ́ pan-kang	empirical: 265 pm
Khiung-ka pan-kang	244±11 pm
Van der Waals pan-kang	343 pm
Miscellanea
Chîn-thí keu-chho	​body-centered cubic (bcc)
Ngie̍t-phàng-chong	97 µm·m−1·K−1 (at 25 °C)
Ngie̍t-chhòn-thô-li̍t	35.9 W·m−1·K−1
Thien-chú-li̍t	205 nΩ·m (at 20 °C)
Chhṳ̀-sin	paramagnetic
Young's modulus	1.7 GPa
Bulk modulus	1.6 GPa
Mohs hardness	0.2
Brinell hardness	0.14 MPa
CAS Registry Number	7440-46-2
Le̍k-sú
Hí-miàng	from Latin caesius, sky blue, for its spectral colours
Fat-hien	Robert Bunsen and Gustav Kirchhoff (1860)
First isolation	Carl Setterberg (1882)
Chui vún-thin ke thùng-vi-su
Chú vùn-chông: caesium ke thùng-vi-su
iso NA half-life DM DE (MeV) DP 133Cs 100% – (SF) <34.753 135Cs trace 2.3×106 y β− 0.269 135Ba 137Cs trace 30.17 y β− 1.174 137Ba
Decay modes in parentheses are predicted, but have not yet been observed

Caesium he yit-chúng fa-ho̍k ngièn-su, fa-ho̍k fù-ho vì Cs, ngièn-chṳ́ su-muk he 55.