Metal | Wikipedia audio article
Channel: wikipedia tts
Date: 2018-12-08

This is an audio version of the Wikipedia Article:
Metal


00:02:50 1 Properties
00:02:59 1.1 Form and structure
00:06:47 1.2 Electrical and thermal
00:08:53 1.3 Chemical
00:09:56 2 Periodic table distribution
00:10:36 3 Alloys
00:12:54 4 Categories
00:13:44 4.1 Ferrous and non-ferrous metals
00:14:13 4.2 Brittle metal
00:14:43 4.3 Refractory metal
00:15:14 4.4 White metal
00:15:51 4.5 Heavy and light metals
00:16:19 4.6 Base, noble and precious metals
00:18:40 5 Lifecycle
00:18:49 5.1 Formation
00:21:10 5.2 Abundance and occurrence
00:23:39 5.3 Extraction
00:25:04 5.4 Uses
00:28:05 5.5 Recycling
00:29:48 6 Biological interactions
00:30:28 7 History
00:30:37 7.1 Prehistory
00:31:31 7.2 Antiquity
00:34:13 7.3 Middle Ages
00:35:46 7.4 The Renaissance
00:38:18 7.5 Light metals
00:40:47 7.6 The age of steel
00:42:17 7.7 The last stable metallic elements
00:44:21 7.8 Post-World War II developments
00:44:30 7.8.1 Superalloys
00:45:17 7.8.2 Transcurium metals
00:46:19 7.8.3 Bulk metallic glasses
00:47:38 7.8.4 Shape-memory alloys
00:48:35 7.8.5 Quasicyrstalline alloys
00:50:39 7.8.6 Complex metallic alloys
00:51:58 7.8.7 High entropy alloys
00:52:40 7.8.8 MAX phase alloys
00:54:14 8 See also



Listening is a more natural way of learning, when compared to reading. Written language only began at around 3200 BC, but spoken language has existed long ago.

Learning by listening is a great way to:
- increases imagination and understanding
- improves your listening skills
- improves your own spoken accent
- learn while on the move
- reduce eye strain

Now learn the vast amount of general knowledge available on Wikipedia through audio (audio article). You could even learn subconsciously by playing the audio while you are sleeping! If you are planning to listen a lot, you could try using a bone conduction headphone, or a standard speaker instead of an earphone.

You can find other Wikipedia audio articles too at:
https://www.youtube.com/channel/UCuKfABj2eGyjH3ntPxp4YeQ

You can upload your own Wikipedia articles through:
https://github.com/nodef/wikipedia-tts



"The only true wisdom is in knowing you know nothing."
- Socrates



SUMMARY
=======
A metal (from Greek μέταλλον métallon, "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and  conducts electricity and heat relatively well. Metals are typically malleable (they can be hammered into thin sheets) or ductile (can be drawn into wires). A metal may be a chemical element such as iron, or an alloy such as stainless steel.
In physics, a metal is generally regarded as any substance capable of conducting electricity at a temperature of absolute zero. Many elements and compounds that are not normally classified as metals become metallic under high pressures. For example, the nonmetal iodine gradually becomes a metal at a pressure of between 40 and 170 thousand times atmospheric pressure. Equally, some materials regarded as metals can become nonmetals. Sodium, for example, becomes a nonmetal at pressure of just under two million times atmospheric pressure.
In chemistry, two elements that would otherwise qualify (in physics) as brittle metals—arsenic and antimony—are commonly instead recognised as metalloids, on account of their predominately non-metallic chemistry. Around 95 of the 118 elements in the periodic table are metals (or are likely to be such). The number is inexact as the boundaries between metals, nonmetals, and metalloids fluctuate slightly due to a lack of universally accepted definitions of the categories involved.
In astrophysics the term "metal" is cast more widely to refer to all chemical elements in a star that are heavier than the lightest two, hydrogen and helium, and not just traditional metals. A star fuses lighter atoms, mostly hydrogen and helium, into heavier atoms over its lifetime. Used in that sense, the metallicity of an astronomical object is the proportion of its matter made up of the heavier chemical elements.Metals comprise 25% of the Earth's crust and are present in many aspects of modern life. The strength and resilience of some metals has led to their frequent use in, for example, high-rise building and bridge construction, as well as most vehicles, many home appliances, tools, pipes, and railroad tracks. Precious metals were historically used as coinage, but in the modern era, coinage metals have extended to at least 23 of the chemical elements.The history of metals is thought to begin with the use of copper about 11,000 years ago. Gold, silver, iron (as meteoric iron), lead, and brass were likewise in use before the first known appearance of bronze in the 5th millennium BCE. Subsequent developments include the production of early forms of steel; the discovery of sodium—the first light metal—in 1809; the rise of modern alloy steels; and, since the end of World War II, the development of more sophisticated alloys.