Polonium

Prepared by:Ian Brunia OranioBEEd 4-B

Prepared for:Asso. Prof. Ignacio S. Tibajares, Jr.Course Facilitator

OverviewName Polonium

Symbol Po

EtymologyAfter “Poland” native country of Curie

Atomic Number 84

Standard Atomic Weight (209)

Metallic Category Post Transition Metal

Group 16

Period 6

Block p

Electron Configuration [Xe] 6s2 4f14 5d10 6p4

Characteristics Polonium is a rare, silvery-gray, radioactive

low-melting metalloid. Polonium readily reacts with dilute acids, but

only slightly with alkalis. All of its isotopes are radioactive. 210Po emits a blue glow, as the air around it is

excited by the decay products.

Proton, Electron, NuetronNo. of Protons (p+) 84

No. of Electrons (e-) 84

No. of Neutrons (n0) 125

The Names Behind Po

Polonium was the first element Marie and Pierre Curie discovered in 1898.

First isolation of Polonium was performed by Willy Marckwald in 1902.

Color Silvery Gray

Density 9.4 g/cm3

Melting Point 527 K, 489 °F 254 °C

Boiling Point 1764 °F 962 °C, 1235 K

Heat of Fusion ca. 13 kJ·mol−1

Heat of Vaporization 102.91 kJ·mol−1

Molar Heat Capacity 26.4 J·mol−1·K−1

Vapor Pressure

Physical Properties

P (Pa) 1 k 10 k 100 kat T (K) (846) 1003 1236

Atomic Properties

Electronegativity 2.0 (Pauling scale)

Ionization Energies 1st: 812.1 kJ·mol−1

Atomic Radius 168 pm

Covalent Radius 140±4 pm

Van der Waals

radius197 pm

Nuclear Properties

Half-Life 102.1 y

Lifetime 147.1 y

Decay Mode Alpha Emission

Quantum Numbers 3P2

Neutron Cross Section 0.5

Known Isotopes188Po, 189Po, 190Po, …, 218Po, 219Po, 220Po

Abundances and Isotopes Abundance earth’s crust: Of the order of 1

part per quadrillion. Abundance solar system: negligible Source: It is found in uranium ores in

minute quantities. Isotopes: Polonium has 29 isotopes whose

half-lives are known, with mass numbers 190 to 218. None are stable. The most stable isotope is 209Po, with a half-life of 102 years.

Production Neutron Capture

It can be obtained by bombarding natural bismuth, 209Bi , with neutrons to give 210Bi, which then decays to 210Po via β decay.

The final purification is done pyrochemically followed by liquid-liquid extraction techniques.

Proton Capture It has been found that the longer-lived

isotopes of polonium can be formed by proton bombardment of bismuth using a cyclotron.

Some Important Uses Nuclear batteries Electrical devices It is used to eliminate static electricity

produced during processes such as rolling paper, wire and sheet metal.

210Po can be used as an atomic heat source. Polonium is also used in anti-static brushes

to eliminate dust on photographic film.

Health Effects

Polonium is harmful both through its chemical toxicity and its radioactivity.

Polonium-210 is an alpha emitter. As such it is very hazardous if swallowed or inhaled.

Exposure to polonium increases the risk of getting various cancers.

A person poisoned by Polonium.