What is Noble Metals?

As it is evident from the reactivity series of metals, silver and gold are the least reactive metals. They do not react with air, water, acids, bases and other substances. So they occur in free state in nature and are known as noble metals. Platinum shows the similar properties and is also a noble metal.
A silver gold and platinum are highly malleable and ductile metals; they can be drawn into extremely thin wires and can be batten into thin sheets and foils. Because of this reason they are used for making jewellery.
Gold is also used for plating other metals such as copper and silver. Platinum is used in dentistry and in making scientific instruments.

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How Many Type of Keys on a Keyboard?

Friends you know a keyboard is the most important part of a computer. It consists of different sets of keys that help us to enter information into the computer. Today we will discuss about keyboard and its keys types and use. A standard keyboard has 104 keys. Types of Keys in a Keyboard: Alphabet Keys Number Keys Special Keys Function Keys Navigation Keys 1. Alphabet Keys: 26 alphabet keys are present on a keyboard from A to Z. these keys are not present in the alphabetical order. These keys are used to type words, sentences or paragraphs. 2. Number Keys: These keys are used for typing numbers. These keys are present above the top row of the alphabet keys and also present on the right side of the keyboard. 3. Special Keys: Keyboard has more special keys such as Space bar Key, caps lock key, backspace key, shift key, enter key, symbol keys and tab key etc. 4. Function Keys: 12 function keys are present on a keyb...

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What is Vacuum Tube

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