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K 19

Potassium (K)

alkali-metal
Periode: 4 Golongan: 1 Blok: s

Solid

Bobot Atom Standar

39,0983 u

Konfigurasi elektron

[Ar] 4s1

Titik lebur

63,38 °C

Titik didih

758,85 °C

Massa jenis

890 kg/m³

Bilangan oksidasi

−1, +1

Keelektronegatifan (Pauling)

0,82

Energi ionisasi (ke-1)

4,340664 eV

Tahun penemuan

1807

Jari-jari atom

220 pm

Detail

Asal nama English: pot ash; symbol from Latin: kalium, (alkali).
Negara penemuan England
Penemu Sir Humphrey Davy

Potassium is an alkali metal and a major rock-forming and biological element. It occurs naturally only in compounds, chiefly as K⁺ in salts, feldspars, micas, and clay minerals. The metal is highly electropositive, reacts vigorously with water, and is stored away from air and moisture. In living cells, potassium is the principal intracellular cation and is central to osmotic balance and electrical signaling.

It is one of the most reactive and electropositive of metals. Except for lithium, it is the lightest known metal. It is soft, easily cut with a knife, and is silvery in appearance immediately after a fresh surface is exposed. It rapidly oxidizes in air and must be preserved in a mineral oil such as kerosene.

As with other metals of the alkali group, it decomposes in water with the evolution of hydrogen. It catches fire spontaneously on water. Potassium and its salts impart a violet color to flames.

The name derives from the English "potash" or "pot ashes" because it is found in caustic potash (KOH). The symbol K derives from the Latin kalium via the Arabic qali for alkali. It was first isolated by the British chemist Humphry Davy in 1807 from electrolysis of potash (KOH).

Although potassium is the eighth most abundant element on earth and comprises about 2.1% of the earth's crust, it is a very reactive element and is never found free in nature. Metallic potassium was first isolated by Sir Humphry Davy in 1807 through the electrolysis of molten caustic potash (KOH). A few months after discovering potassium, Davy used the same method to isolate sodium. Potassium can be obtained from the minerals sylvite (KCl), carnallite (KCl·MgCl2·6H2O), langbeinite (K2Mg2(SO4)3) and polyhalite (K2Ca2Mg(SO4)4·2H2O). These minerals are often found in ancient lake and sea beds. Caustic potash, another important source of potassium, is primarily mined in Germany, New Mexico, California and Utah. Pure potassium is a soft, waxy metal that can be easily cut with a knife. It reacts with oxygen to form potassium superoxide (KO2) and with water to form potassium hydroxide (KOH), hydrogen gas and heat. Enough heat is produced to ignite the hydrogen gas. To prevent it from reacting with the oxygen and water in the air, samples of metallic potassium are usually stored submerged in mineral oil.

From the English word, potash - pot ashes; Latin kalium, Arab qali, alkali. Discovered in 1807 by Davy, who obtained it from caustic potash (KOH); this was the first metal isolated by electrolysis.

Gambar

Sifat

Fisika

Jari-jari atom (empiris)
220 pm Bandingkan Jari-jari atom (empiris) semua unsur →
Jari-jari kovalen
203 pm Bandingkan Jari-jari kovalen semua unsur →
Jari-jari van der Waals
275 pm Bandingkan Jari-jari van der Waals semua unsur →
Jari-jari logam
203 pm Bandingkan Jari-jari logam semua unsur →
Massa jenis
890 kg/m³ Bandingkan Massa jenis semua unsur →
Volume molar
0,0453 L/mol
Fase pada STP
Padat Bandingkan Fase pada STP semua unsur →
Titik lebur
63,38 °C Bandingkan Titik lebur semua unsur →
Titik didih
758,85 °C Bandingkan Titik didih semua unsur →
Konduktivitas termal
79 W/(m·K) Bandingkan Konduktivitas termal semua unsur →
Kapasitas kalor spesifik
0,757 J/(g·K) Bandingkan Kapasitas kalor spesifik semua unsur →
Kapasitas kalor molar
29,6 J/(mol·K) Bandingkan Kapasitas kalor molar semua unsur →
Struktur kristal
Kubik berpusat badan Bandingkan Struktur kristal semua unsur →

Kimia

Keelektronegatifan (Pauling)
0,82 Bandingkan Keelektronegatifan (Pauling) semua unsur →
Keelektronegatifan (Allen)
0,734
Afinitas elektron
0,5014 eV
Energi ionisasi (ke-1)
4,340664 eV Bandingkan Energi ionisasi (ke-1) semua unsur →
Energi ionisasi (ke-2)
31,625109 eV Bandingkan Energi ionisasi (ke-2) semua unsur →
Energi ionisasi (ke-3)
45,803258 eV Bandingkan Energi ionisasi (ke-3) semua unsur →
Energi ionisasi (ke-4)
60,91721 eV Bandingkan Energi ionisasi (ke-4) semua unsur →
Energi ionisasi (ke-5)
82,660285 eV Bandingkan Energi ionisasi (ke-5) semua unsur →
Bilangan oksidasi
−1, +1 Bandingkan Bilangan oksidasi semua unsur →
Elektron valensi
1 Bandingkan Elektron valensi semua unsur →
Konfigurasi elektron
[Ar] 4s1

Termodinamika

Titik kritis (suhu)
1950 °C
Titik kritis (tekanan)
1,6e+7 Pa
Kalor peleburan
0,02414883 eV Bandingkan Kalor peleburan semua unsur →
Kalor penguapan
0,79701508 eV Bandingkan Kalor penguapan semua unsur →
Kalor sublimasi
0,92449604 eV
Kalor atomisasi
0,92449604 eV
Entalpi atomisasi
0,92242317 eV

Nuklir

Proton
19 Bandingkan Proton semua unsur →
Neutron
20 Bandingkan Neutron semua unsur →
Isotop yang diketahui
29 Bandingkan Isotop yang diketahui semua unsur →
Isotop stabil
2 Bandingkan Isotop stabil semua unsur →
Isotop paling stabil
K-39
Tahun penemuan
1807

Kelimpahan

Kelimpahan (kerak Bumi)
2,09e+4 mg/kg Bandingkan Kelimpahan (kerak Bumi) semua unsur →
Kelimpahan (samudra)
399 mg/L Bandingkan Kelimpahan (samudra) semua unsur →

Struktur Kristal

Konstanta kisi a
523 pm

Struktur Elektronik

Elektron per kulit
2, 8, 8, 1 Bandingkan Elektron per kulit semua unsur →

Pengenal

Nomor CAS
7440-09-7 Bandingkan Nomor CAS semua unsur →
Simbol term
2S1/2
InChI
InChI=1S/K
Kunci InChI
ZLMJMSJWJFRBEC-UHFFFAOYSA-N

Konfigurasi Elektron Diukur

Muatan ion
Proton 19
Elektron 19
Muatan Netral
Konfigurasi K: 4s¹
Konfigurasi elektron
Diukur
[Ar] 4s¹
1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹
Diagram orbital
1s
2/2
2s
2/2
2p
6/6
3s
2/2
3p
6/6
4s
1/2 1↑
Total elektron: 19 Tidak berpasangan: 1 ?

Model atom

Proton 19
Neutron 20
Elektron 19
Nomor massa 39
Kestabilan Stabil

Isotop mengubah jumlah neutron, massa, dan kestabilan — bukan konfigurasi elektron atom netral.

Model atom skematis, tidak sesuai skala.

Sidik Jari Atom

Spektrum Emisi / Absorpsi

25 / 50 (50 50 dengan intensitas)
Diukur
Emisi Tampak: 380–750 nm

Distribusi Isotop

3993,2581%416,7302%Nomor massaKelimpahan alami (%)
Nomor massaMassa atom (u)Kelimpahan alamiWaktu paruh
39 Stabil38,9637064864 ± 0,000000004993,2581%Stabil
41 Stabil40,9618252579 ± 0,00000000416,7302%Stabil
Diukur

Fase / Wujud

1 atm / 101.325 kPa
Padat 25 °C (298,15 K)

Alasan: 38,4 °C di bawah titik lebur (63,38 °C)

Titik lebur 63,38 °C
Titik didih 758,85 °C
Di bawah titik lebur sebesar 38,4 °C
0 K Suhu saat ini: 25 °C 6000 K
Linimasa fase

Skematis, tidak sesuai skala

Padat
Cair
Gas
Peleburan
Pendidihan
25°C
Padat
Cair
Gas
Saat ini

Titik transisi fase

Titik lebur Literatur
63,38 °C
Titik didih Literatur
758,85 °C
Fase saat ini Dihitung
Padat

Energi transisi

Kalor peleburan Literatur
0,02414883 eV

Energi yang diperlukan untuk meleburkan 1 mol pada titik lebur

Kalor penguapan Literatur
0,79701508 eV

Energi yang diperlukan untuk menguapkan 1 mol pada titik didih

Kalor sublimasi Literatur
0,92449604 eV

Energi yang diperlukan untuk menyublimkan 1 mol pada titik sublimasi

Massa jenis

Massa jenis referensi Literatur
890 kg/m³

Pada kondisi standar

Massa jenis saat ini Dihitung
890 kg/m³

Pada kondisi standar

Lanjutan

Titik kritis Literatur
1950 °C

Spektrum Atom

Menampilkan 10 dari 22. Diurutkan berdasarkan muatan ion (menaik).

Data Tingkat Energi ?

IonMuatanTingkat energi
41K I Isotop08
40K I Isotop03
39K I Isotop0123
K I 0299
K II +197
K III +240
K IV +338
K V +440
K VI +528
K VII +681
Data Tingkat Energi NIST →
19 K 39.0983

Potassium — Visualisasi Orbital Atom

[Ar]4s1
Tingkat energi 2 8 8 1
Bilangan oksidasi -1, +1
HOMO 4s n=4 · l=0 · m=0
Potassium — Pratinjau Visualisasi Orbital Atom
Three.js hanya dimuat saat diminta
19 K 39.0983

Potassium — Visualisasi Struktur Kristal

Kubik Berpusat Badan · Pearson cI2
Eksperimental
Pearson cI2
No. Koord. 8
Pengemasan 68.000%
Potassium — Pratinjau Visualisasi Struktur Kristal
Three.js hanya dimuat saat diminta

Jari-jari Ion

MuatanKoordinasiSpinJari-jari
+14Tidak tersedia137 pm
+16Tidak tersedia138 pm
+17Tidak tersedia146 pm
+18Tidak tersedia151 pm
+19Tidak tersedia155 pm
+110Tidak tersedia159 pm
+112Tidak tersedia164 pm

Senyawa

K+
39,098 u
K
39,098 u
K
39,964 u
K
42,961 u
K
41,962 u
K
37,969 u
K
38,964 u
K
43,962 u
K
44,961 u
K+
39,964 u
K+
37,969 u
K+
38,964 u
K+
42,961 u
K+
41,962 u
K
40,962 u

Isotop (2)

Seventeen isotopes of potassium are known. Ordinary potassium is composed of three isotopes, one of which is 40°K (0.0118%), a radioactive isotope with a half-life of 1.28 x 109 years.

Nomor massaMassa atom (u)Kelimpahan alamiWaktu paruhMode peluruhan
39 Stabil38,9637064864 ± 0,000000004993,2581% ± 0,0044%Stabil
stable
41 Stabil40,9618252579 ± 0,00000000416,7302% ± 0,0044%Stabil
stable
39 Stabil
Massa atom (u) 38,9637064864 ± 0,0000000049
Kelimpahan alami 93,2581% ± 0,0044%
Waktu paruh Stabil
Mode peluruhan
stable
41 Stabil
Massa atom (u) 40,9618252579 ± 0,0000000041
Kelimpahan alami 6,7302% ± 0,0044%
Waktu paruh Stabil
Mode peluruhan
stable

Garis Spektrum

Menampilkan 50 dari 141. Secara bawaan, hanya garis spektrum dengan intensitas terukur yang ditampilkan.

Panjang gelombang (nm)IntensitasTahap ionisasiJenisTransisiAkurasiSumber
693.8764 nm20K Iemission3p6.4p 2P* → 3p6.6s 2SDiukurNIST
691.10815 nm19K Iemission3p6.4p 2P* → 3p6.6s 2SDiukurNIST
404.41422 nm18K Iemission3p6.4s 2S → 3p6.5p 2P*DiukurNIST
404.72132 nm17K Iemission3p6.4s 2S → 3p6.5p 2P*DiukurNIST
580.17662 nm17K Iemission3p6.4p 2P* → 3p6.7s 2SDiukurNIST
583.18899 nm17K Iemission3p6.4p 2P* → 3p6.5d 2DDiukurNIST
578.23999 nm16K Iemission3p6.4p 2P* → 3p6.7s 2SDiukurNIST
581.21521 nm15K Iemission3p6.4p 2P* → 3p6.5d 2DDiukurNIST
535.95761 nm14K Iemission3p6.4p 2P* → 3p6.6d 2DDiukurNIST
533.96873 nm13K Iemission3p6.4p 2P* → 3p6.8s 2SDiukurNIST
511.225448 nm12K Iemission3p6.4p 2P* → 3p6.7d 2DDiukurNIST
532.32786 nm12K Iemission3p6.4p 2P* → 3p6.8s 2SDiukurNIST
534.29693 nm12K Iemission3p6.4p 2P* → 3p6.6d 2DDiukurNIST
693.62861 nm12K Iemission3p6.4p 2P* → 3p6.4d 2DDiukurNIST
696.46903 nm12K Iemission3p6.4p 2P* → 3p6.4d 2DDiukurNIST
464.23725 nm11K Iemission3p6.4s 2S → 3p6.3d 2DDiukurNIST
509.717137 nm11K Iemission3p6.4p 2P* → 3p6.7d 2DDiukurNIST
509.920005 nm11K Iemission3p6.4p 2P* → 3p6.9s 2SDiukurNIST
464.1875 nm10K Iemission3p6.4s 2S → 3p6.3d 2DDiukurNIST
496.503213 nm10K Iemission3p6.4p 2P* → 3p6.8d 2DDiukurNIST
508.423399 nm10K Iemission3p6.4p 2P* → 3p6.9s 2SDiukurNIST
482.924 nm9K IIemission3p5.4s 3P* → 3p5.4p 3SDiukurNIST
486.975897 nm9K Iemission3p6.4p 2P* → 3p6.9d 2DDiukurNIST
495.081801 nm9K Iemission3p6.4p 2P* → 3p6.8d 2DDiukurNIST
495.614802 nm9K Iemission3p6.4p 2P* → 3p6.10s 2SDiukurNIST
389.7896 nm8K IIemission3p5.4s 3P* → 3p5.4p 1DDiukurNIST
418.6232 nm8K IIemission3p5.4s 3P* → 3p5.4p 3DDiukurNIST
460.849 nm8K IIemission3p5.4s 1P* → 3p5.4p 1DDiukurNIST
480.43395 nm8K Iemission3p6.4p 2P* → 3p6.10d 2DDiukurNIST
485.609209 nm8K Iemission3p6.4p 2P* → 3p6.9d 2DDiukurNIST
486.348075 nm8K Iemission3p6.4p 2P* → 3p6.11s 2SDiukurNIST
500.564 nm8K IIemission3p5.4s 3P* → 3p5.4p 3SDiukurNIST
612.028 nm8K IIemission3p5.3d 3F* → 3p5.4p 3DDiukurNIST
381.7547 nm7K IIemission3p5.4p 3D → 3p5.(2P*<3/2>).5s 2[3/2]*DiukurNIST
400.122 nm7K IIemission3p5.4s 3P* → 3p5.4p 3PDiukurNIST
413.4705 nm7K IIemission3p5.4s 3P* → 3p5.4p 3DDiukurNIST
422.296 nm7K IIemission3p5.4s 1P* → 3p5.4p 3PDiukurNIST
422.566 nm7K IIemission3p5.3d 3P* → 3p5.4p 1DDiukurNIST
426.334 nm7K IIemission3p5.4s 3P* → 3p5.4p 3DDiukurNIST
430.498 nm7K IIemission3p5.3d 3P* → 3p5.4p 1DDiukurNIST
430.911 nm7K IIemission3p5.4s 1P* → 3p5.4p 3PDiukurNIST
438.816 nm7K IIemission3p5.4s 1P* → 3p5.4p 1PDiukurNIST
475.737719 nm7K Iemission3p6.4p 2P* → 3p6.11d 2DDiukurNIST
479.104132 nm7K Iemission3p6.4p 2P* → 3p6.10d 2DDiukurNIST
484.98645 nm7K Iemission3p6.4p 2P* → 3p6.11s 2SDiukurNIST
505.625 nm7K IIemission3p5.3d 3P* → 3p5.4p 3SDiukurNIST
630.728 nm7K IIemission3p5.3d 3F* → 3p5.4p 3DDiukurNIST
696.41712 nm7K Iemission3p6.4p 2P* → 3p6.4d 2DDiukurNIST
380.0162 nm6K IIemission3p5.4p 3D → 3p5.(2P*<3/2>).5s 2[3/2]*DiukurNIST
381.657 nm6K IIemission3p5.4p 3P → 3p5.4d 3P*DiukurNIST

Sifat Lanjutan

Jari-jari Kovalen (Lanjutan)

Jari-jari kovalen (Pyykkö)
196 pm
Jari-jari kovalen (Pyykkö, ikatan rangkap dua)
193 pm
Jari-jari kovalen (Bragg)
207 pm

Jari-jari van der Waals

Bondi
275 pm
Batsanov
280 pm
Alvarez
273 pm
UFF
381,2 pm
MM3
309 pm

Jari-jari Atom & Logam

Jari-jari atom (Rahm)
234 pm
Jari-jari logam (C12)
235 pm

Skala Penomoran

Mendeleev
3
Pettifor
10
Glawe
10

Skala Keelektronegatifan

Ghosh
0
Miedema
2
Gunnarsson–Lundqvist
2
Robles–Bartolotti
1

Polarizabilitas & Dispersi

Polarizabilitas dipol
289,7 a.u.
Polarizabilitas dipol (ketidakpastian)
0,3 a.u.
C₆
3923 Ha·Bohr6
C₆ (Gould–Bučko)
3910 Ha·Bohr6

Parameter Miedema

Volume molar Miedema
45,63 cm3/mol
Kerapatan elektron Miedema
0

Risiko Pasokan & Ekonomi

Konsentrasi produksi
21
Risiko pasokan relatif
5
Distribusi cadangan
61
Stabilitas politik (produsen terbesar)
81
Stabilitas politik (pemilik cadangan terbesar)
81

Transisi Fase & Alotrop

Titik lebur336,65 K
Titik didih1032,15 K
Titik kritis (suhu)2223,15 K
Titik kritis (tekanan)16 MPa

Kategori Bilangan Oksidasi

+1 main
−1 extended

Data Referensi Lanjutan

Konstanta Pemerisaian (6)
nOrbitalσ
1s0,5105
2p3,9728
2s5,9938
3p11,2744
3s10,3201
4s15,5048
Detail Jari-jari Kristal (7)
MuatanCNSpinrcrystal (pm)Asal
1IV151
1VI152
1VII160
1VIII165
1IX169
1X173
1XII178
Mode Peluruhan Isotop (53)
IsotopModeIntensitas
313p100%
32p—
33p—
34p—
35B+100%
35B+p0,4%
36B+100%
36B+p0%
36B+A0%
37B+100%
Faktor Hamburan Sinar-X (503)
Energi (eV)f₁f₂
10—0,03426
10,1617—0,03529
10,3261—0,03635
10,4931—0,03744
10,6628—0,03856
10,8353—0,03972
11,0106—0,04091
11,1886—0,04214
11,3696—0,0434
11,5535—0,04471

Data Tambahan

Sources

Sources of this element.

The metal is the seventh most abundant and makes up about 2.4% by weight of the earth's crust. Most potassium minerals are insoluble and the metal is obtained from them only with great difficulty.

Certain minerals, however, such as sylvite, carnallite, langbeinite, and polyhalite are found in ancient lake and sea beds and form rather extensive deposits from which potassium and its salts can readily be obtained. Potash is mined in Germany, New Mexico, California, Utah, and elsewhere. Large deposits of potash, found at a depth of some 3000 ft in Saskatchewan, promise to be important in coming years.

Potassium is also found in the ocean, but is present only in relatively small amounts, compared to sodium.

Referensi (1)

Production

Production of this element (from raw materials or other compounds containing the element).

Potassium is never found free in nature, but is obtained by electrolysis of the hydroxide, much in the same manner as prepared by Davy's first process. Thermal methods also are commonly used to produce potassium (such as by reduction of potassium compounds with CaC2, C, Si, or Na).

Referensi (1)

Referensi

(9)
2 Atomic Mass Data Center (AMDC), International Atomic Energy Agency (IAEA)
K

The half-life and atomic mass data was provided by the Atomic Mass Data Center at the International Atomic Energy Agency.

3 IUPAC Commission on Isotopic Abundances and Atomic Weights (CIAAW)
Potassium

Element data are cited from the Atomic weights of the elements (an IUPAC Technical Report). The IUPAC periodic table of elements can be found at https://iupac.org/what-we-do/periodic-table-of-elements/. Additional information can be found within IUPAC publication doi:10.1515/pac-2015-0703 Copyright © 2020 International Union of Pure and Applied Chemistry.

4 IUPAC Periodic Table of the Elements and Isotopes (IPTEI)

The information are cited from Pure Appl. Chem. 2018; 90(12): 1833-2092, https://doi.org/10.1515/pac-2015-0703.

Catatan lisensi: Copyright (c) 2020 International Union of Pure and Applied Chemistry. The International Union of Pure and Applied Chemistry (IUPAC) contribution within Pubchem is provided under a CC-BY-NC-ND 4.0 license, unless otherwise stated.
5 Jefferson Lab, U.S. Department of Energy
Potassium

Thomas Jefferson National Accelerator Facility (Jefferson Lab) is one of 17 national laboratories funded by the U.S. Department of Energy. The lab's primary mission is to conduct basic research of the atom's nucleus using the lab's unique particle accelerator, known as the Continuous Electron Beam Accelerator Facility (CEBAF). For more information visit https://www.jlab.org/

Catatan lisensi: Please see citation and linking information: https://education.jlab.org/faq/index.html
6 Los Alamos National Laboratory, U.S. Department of Energy
Potassium

The periodic table at the LANL (Los Alamos National Laboratory) contains basic element information together with the history, source, properties, use, handling and more. The provenance data may be found from the link under the source name.

7 NIST Physical Measurement Laboratory
Potassium

The periodic table contains NIST's critically-evaluated data on atomic properties of the elements. The provenance data that include data for atomic spectroscopy, X-ray and gamma ray, radiation dosimetry, nuclear physics, and condensed matter physics may be found from the link under the source name. Ref: https://www.nist.gov/pml/atomic-spectra-database

8 PubChem Elements
Potassium

This section provides all form of data related to element Potassium.

9 PubChem Elements
Potassium

The element property data was retrieved from publications.

Terakhir diperbarui:

Data terverifikasi:

Konten ditinjau berdasarkan data ilmiah terbaru.