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II (Past Participle)




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The described method is widely used in electroplating. .

 

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A substance is composed of tiny particles called molecules. , .

 

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Placed in a vessel, a gas fills it completely. A gas placed in a vessel fills it completely. .

 

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When heated, mercuric oxide decomposes rather readily. .

 

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When heated solids expand little as compared with liquids.

 

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1. The force of gravitational attraction exerted on a body by the earth known as the weight of the body is one of the most important forces in everyday life. 2. The total quantity of pure radium obtained is quite insignificant. 3. Intermolecular space exists even in a gas which, subjected to exceedingly high pressure, ceases to contract its volume. 4. When used as an amplifier the radio-tube allows a small voltage to control a strong flow of current from a battery. 5. If a body is totally immersed in a fluid, the upthrust of the fluid on the body is equal to the weight of the fluid displaced. 6. When the water has reached the boiling point, the temperature ceases to rise, and the heat supplied is used in changing the water into steam. 7. A beaker filled with cold water and held over a flame of burning hydrogen will condense the steam to droplets of water. 8. Glass and porcelain neither lose nor gain in weight when heated. 9. Any open mass of water if left unreplenished will evaporate little by little. 10. The modern war is an allround test of the material and spiritual strength of every nation involved. 11. Under ordinary pressure a given liquid boils at a fixed temperature. 12. Nitre gives off oxygen only when raised to a brightred heat. 13. The efficiency of a machine is determined by the radio of the useful work performed to the total work expended. 14. Radioisotopes produced by our atomic industry are widely used in medicine and agriculture. 15. Capacity is the property of two electrical conductors, when separated by insulation, to receive and retain electricity. 16. Fermentation used for producing alcohol from naturally occurring substances is one of the oldest processes known to man. 17. Alloys in general consist of two or more metals melted together and then allowed to solidify. 18. The properties of matter are better learned and understood when correlated with its structure in terms of molecules, atoms, and still smaller particles. 19. When ozone decomposes, the amount of energy liberated is equivalent to that absorbed in its formation. 20. Some liquids, and to a much smaller extent some solids, if placed in contact, tend to diffuse one into the other.

 

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BORAX

 

This salt, when crystallized from solution, combines with water forming a hydrate. It is made by adding calcium borate to sodium carbonate solution. It is a white crystalline salt. It is added to the glass, used for enameling and glazing, to make it more fusible and easier to spread in a thin layer. Since it contains but a small proportion of the metallic oxide, it combines with other metallic oxides if fused with them. For this reason, the powdered salt is sometimes sprinkled on tarnished metallic surfaces being soldered or brazed. The heat of the blowpipe melts the borax and the latter removes the oxide and permits perfect running of the solder over the surface.

The borates thus formed are often colored and the colors afford a means of recognizing the metallic compound which produced them.

In chemical analyses a bead of borax, produced by fusion on a platinum wire, is heated with a particle of the unknown compound and its color then examined.

 

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