Pemalar fizik

Dalam fizik, pemalar fizik merupakan kuantiti fizikal yang dipercayai mempunyai nilai sejagat yang tetap (malar). Ia dikira daripada kuantiti fizikal yang lain.

Contohnya, cas asas, e mempunyai nilai 1.602 176 487 × 10^-19 C.

Jadual pemalar universal

Kuantiti	Simbol	Nilai	Ketakpastian relatif piawai
impedans vakum berciri	${\displaystyle Z_{0}=\mu _{0}c\,}$	376.730 313 461... Ω	ditakrif
pemalar elektrik (ketelusan vakum)	${\displaystyle \epsilon _{0}=1/(\mu _{0}c^{2})\,}$	8.854 187 817... × 10-12F·m-1	ditakrif
pemalar magnet (ketelusan vakum)	${\displaystyle \mu _{0}\,}$	4π × 10-7 N·A-2 = 1.256 637 061... × 10-6 N·A-2	ditakrif
pemalar graviti	${\displaystyle G\,}$	6.67428(67) × 10-11m3·kg-1·s-2	1.0 × 10-4
pemalar Planck	${\displaystyle h\,}$	6.626 068 96(33) × 10-34 J·s	5.0 × 10-8
pemalar Dirac (pemalar Planck terturun)	${\displaystyle \hbar =h/(2\pi )}$	1.054 571 628(53) × 10-34 J·s	5.0 × 10-8
kelajuan cahaya di vakum	${\displaystyle c\,}$	299 792 458 m·s-1	ditakrif

Pemalar fizik-kimia

Kuantiti		Simbol	Nilai1 (SI)	Ketakpastian relatif piawai
unit jisim atom		${\displaystyle m_{u}=1\ u\,}$	1.660 538 86(28) × 10-27 kg	1.7 × 10-7
pemalar Avogadro		${\displaystyle N_{A},L\,}$	6.022 1415(10) × 1023	1.7 × 10-7
pemalar Boltzmann		${\displaystyle k=R/N_{A}\,}$	1.380 6505(24) × 10-23 J·K-1	1.8 × 10-6
pemalar Faraday		${\displaystyle F=N_{A}e\,}$	96 485.3383(83)C·mol-1	8.6 × 10-8
pemalar sinaran pertama	${\displaystyle c_{1}=2\pi hc^{2}\,}$	3.741 771 38(64) × 10-16 W·m2	1.7 × 10-7
	bagi kesinaran spektrum	${\displaystyle c_{1L}\,}$	1.191 042 82(20) × 10-16 W · m2 sr-1	1.7 × 10-7
pemalar Loschmidt	at ${\displaystyle T}$=273.15 K and ${\displaystyle p}$=101.325 kPa	${\displaystyle n_{0}=N_{A}/V_{m}\,}$	2.686 7773(47) × 1025 m-3	1.8 × 10-6
pemalar gas		${\displaystyle R\,}$	8.314 472(15) J·K-1·mol-1	1.7 × 10-6
pemalar Planck molar		${\displaystyle N_{A}h\,}$	3.990 312 716(27) × 10-10 J · s · mol-1	6.7 × 10-9
isi padu molar gas ideal	at ${\displaystyle T}$=273.15 K and ${\displaystyle p}$=100 kPa	${\displaystyle V_{m}=RT/p\,}$	22.710 981(40) × 10-3 m3 ·mol-1	1.7 × 10-6
	pada ${\displaystyle T}$=273.15 K and ${\displaystyle p}$=101.325 kPa		22.413 996(39) × 10-3 m3 ·mol-1	1.7 × 10-6
pemalar Sackur-Tetrode	at ${\displaystyle T}$=1 K and ${\displaystyle p}$=100 kPa	${\displaystyle S_{0}/R={\frac {5}{2}$ ${\displaystyle +\ln \left[(2\pi m_{u}kT/h^{2})^{3/2}kT/p\right]}$	-1.151 7047(44)	3.8 × 10-6
	pada ${\displaystyle T}$=1 K and ${\displaystyle p}$=101.325 kPa		-1.164 8677(44)	3.8 × 10-6
pemalar sinaran kedua		${\displaystyle c_{2}=hc/k\,}$	1.438 7752(25) × 10-2 m·K	1.7 × 10-6
pemalar Stefan-Boltzmann		${\displaystyle \sigma =(\pi ^{2}/60)k^{4}/\hbar ^{3}c^{2}$	5.670 400(40) × 10-8 W·m-2·K-4	7.0 × 10-6
pemalar hukum sesaran Wien		${\displaystyle b=(hc/k)/\,}$ 4.965 114 231...	2.897 7685(51) × 10-3 m · K	1.7 × 10-6

Nilai diakui

Kuantiti		Simbol	Nilai (SI)	Ketakpastian relatif piawai
pemalar Josephson2		${\displaystyle K_{J-90}\,}$	483 597.9 × 109 Hz · V-1	ditakrif
pemalar von Klitzing3		${\displaystyle R_{K-90}\,}$	25 812.807 Ω	ditakrif
jisim molar	pemalar	${\displaystyle M_{u}=M(\,^{12}{\mbox{C})/12}$	1 × 10-3 kg · mol-1	ditakrif
	bagi karbon-12	${\displaystyle M(\,^{12}{\mbox{C})=N_{A}m(\,^{12}{\mbox{C})}$	12 × 10-3 kg · mol−1	ditakrif
pecutan graviti		${\displaystyle g_{n}\,\!}$	9.806 65 m·s-2	ditakrif
atmosfera piawai		${\displaystyle {\mbox{atm}\,}$	101 325 Pa	ditakrif