Chemical elements
    Physical Properties
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    PDB 12ca-1ai0
    PDB 1aiy-1b6z
    PDB 1b71-1bs8
    PDB 1bsk-1cao
    PDB 1caq-1ctt
    PDB 1ctu-1de6
    PDB 1def-1dy0
    PDB 1dy1-1ed6
    PDB 1ed8-1exk
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    PDB 1fjg-1g0e
    PDB 1g0f-1gkq
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    PDB 1iml-1jcv
    PDB 1jcz-1jy8
    PDB 1jyb-1kh4
    PDB 1kh5-1kys
    PDB 1kzo-1llm
    PDB 1llu-1m7j
    PDB 1m9j-1mwo
    PDB 1mwq-1ndv
    PDB 1ndw-1nyq
    PDB 1nyr-1os4
    PDB 1os9-1p9w
    PDB 1paa-1pud
    PDB 1pv8-1q9l
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    PDB 1r79-1ro9
    PDB 1ror-1sfo
    PDB 1sg0-1t3k
    PDB 1t4k-1tkh
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    PDB 1u10-1ums
    PDB 1umt-1v67
    PDB 1v6g-1vrq
    PDB 1vs0-1wew
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    PDB 1wwg-1xb1
    PDB 1xb8-1xpz
    PDB 1xq0-1y5w
    PDB 1y5x-1ylk
    PDB 1ylo-1z8r
    PDB 1z93-1zkx
    PDB 1zl6-258l
    PDB 2a03-2afo
    PDB 2afs-2atq
    PDB 2au3-2bfz
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    PDB 2vz5-2wey
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    PDB 2xrg-2ytd
    PDB 2yte-2z30
    PDB 2z3g-2zet
    PDB 2zh0-3a32
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    PDB 3d09-3dbu
    PDB 3dc3-3dp6
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    PDB 3ebi-3epk
    PDB 3epl-3f28
    PDB 3f2b-3fhe
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    PDB 3fum-3g9y
    PDB 3ga3-3gpu
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    PDB 3hso-3i8v
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    PDB 3ijf-3ixe
    PDB 3iz0-3k34
    PDB 3k35-3kiy
    PDB 3kj1-3kvt
    PDB 3kwa-3lat
    PDB 3lcn-3lrr
    PDB 3ls1-3m1n
    PDB 3m1v-3mek
    PDB 3men-3mru
    PDB 3ms0-3n63
    PDB 3n64-3nin
    PDB 3nis-3ny2
    PDB 3ny3-3ohc
    PDB 3ohd-3oyl
    PDB 3oym-3pih
    PDB 3pki-3r0d
    PDB 3rj7-3t74
    PDB 3t87-3u9g
    PDB 3ua7-3v24
    PDB 3v25-4agl
    PDB 4agm-4dih
    PDB 4dii-4efs
    PDB 4eg2-4fc8
    PDB 4fgm-6tli
    PDB 6tmn-9nse

Physical Properties of Zinc

Zinc is a greyish-white or bluish-white metal. It has a metallic lustre, can take a high polish, and tarnishes quickly in ordinary air.

Zinc is said to undergo allotropic modification from an a-variety to a β-variety at 174° C., and from the β-variety to a γ-variety at 322° C. According to Cohen and Heldermann, ordinary zinc is a metastable mixture of several allotropic modifications, and " atomised " zinc is also a mixture of two or more allotropic forms.

Zinc sublimes in a crystalline form when it is distilled in hydrogen or in vacuo. The crystals were supposed to occur dimorphically in the regular and hexagonal systems, but crystalline zinc is, however, apparently hexagonal and probably holohedral.

When zinc is crushed its micro-structure becomes homogeneous and its hardness increases. Annealing restores the crystalline structure. The cast metal " cries " more feebly than tin.

It is brittle at ordinary temperatures, but becomes malleable and ductile at 100°-150° C. The metal is rolled hot on the large scale, but it remains sufficiently malleable after heating to be rolled or drawn into wire. Above 205° C. the metal again becomes brittle enough to be pulverised in a mortar.

Zinc is distinctly plastic at 200°-400° C., and the warm metal can be pressed through an opening.

The modulus of elasticity, or Young's modulus of zinc, has been given as varying between 7670 and 10,550, or an average of 9300 kgm. per sq. mm.: it varies with the nature and purity of the metal.

In determinations of the tensile strength the breaking load of thin rolled zinc was found to be about 24,000 lb. per sq. inch, and the tension modulus of elasticity 11,500,000 lb. per sq. inch.

The average compressibility of zinc, the fractional change of volume produced by one megabar pressure, is 1.5×10-6 per unit volume per megabar, between 100 and 500 megabars.

The hardness of zinc seems to be 2.5 on Mohs' scale, but it varies with the purity of the metal, and perfectly pure zinc seems to be softer than silver.

The density of distilled zinc at 20°/24° C. is 6.9225, which rises to 7.12722 after compression under 10,000 atmospheres, but it varies with the history of the metal and usually diminishes on "working."

Schiff found that the density of granulated zinc at 12° C. varied from 6.966 to 6.975, and recorded determinations by other observers from 6.861 to 7.1908. According to Kalischer, a specimen of rolled zinc of density 7.1812 had a density of 7.1841 when it became crystalline by heating to 130°-300° C. (Water at 0° C. = 1.)

The density of zinc decreases on melting. One grm. of zinc was found to expand by 0.010 c.c. on melting, the corresponding densities have been estimated at 7.2 and 6.48, and the density of molten zinc is expressed by the formula

D = 6.59 – 0.00097 (t – 419)

at any temperature t. The slight contraction during solidification adapts the metal for castings.

The vapour density of zinc corresponds to a monatomic molecule. When zinc dissolves in mercury it depresses the vapour pressure as if its molecule were monatomic.

Zinc melts at 419.4° C. There has been a gradual convergence on this figure during the progress of research.

The latent heat of fusion of zinc is about 1.730 Cal.

Berthelot found 920° C. for the boiling-point of zinc. Higher temperatures had been found by earlier investigators. More recently 918° C. has been assigned as the boiling-point.

In vacuo zinc volatilises slowly at 184° C. and boils at 550° C. According to Heycock and Lamplough, the boiling-point alters by 0.133° C. per mm. difference from normal pressure.

The latent heat of vaporisation at boiling-point is 31.430 Cal. The specific heat varies from 0.08421 at -127.5° C. to 0.09570 at 123.5° C. From the mean of determinations by Naccari, Bede, and Schliibel, the specific heat of zinc is 0.0929 between 18° C. and 100° C., 0.0957 between 18° C. and 200° C., and 0.0978 between 18° C. and 300° C. According to Kahlbaum, Roth, and Siedler, the specific heat of distilled zinc is 0.0939, which becomes 0.0940 after compression.

The thermal conductivity decreases with the temperature up to the melting-point. Then there is a sharp drop, succeeded by another gradual rise. According to Lees, the thermal conductivity of pure, redistilled cast zinc varies from 0.20 at -170° C. to 0.268 at 18° C. According to Jager and Diesselhorst it is 0.265 at 18° C. for pure cast zinc and 0.262 at 100° C.

The electrical conductivity in reciprocal ohms per cm. cube varies from 19.5×104 at -170° C. to 16.9×104 at 18° C. The conductivity has been expressed as 5.45 (l+0.0039t+0.0000017t2) microhms at any temperature t between 15° C. and 300° C.

Breaks in the thermal and electrical conductivity curves have been connected with allotropic modifications of zinc.

The coefficient of linear expansion is 10.06×10-6 between -183° C. and 12.6° C., and 17.11×10-6 between 19.3° C. and 100.2° C.

The most important lines in the arc spectrum of zinc, in Angstrom (10-8 cm.) units, are: 3036, 3072, 3345, 4630.06, 4680.138, 4722.164, 4810.535, 4912, 4925, 6103, 6362.345.

Colloidal Zinc

A fairly stable colloidal solution of zinc in ether has been obtained by sparking between zinc electrodes immersed in the liquid.

Colloidal solutions can be prepared by electrical discharge between zinc electrodes under water, but they are more unstable than corresponding cadmium solutions.

The colloidal solution of zinc in isobutyl alcohol, obtained by an electrical method, is stable. It is brownish red by transmitted light and greyish black by reflected.
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