Question

Purity of gold is expressed in ____________

Answer 1

Hint: We must know about Gold, Gold is a very rare chemical compound denoted with the symbol \[Au\] (Latin name=aurum) and with an atomic number of 79, making it a high number compound that is being naturally found in the environment. The purity of all precious metals depends on the combination of the alloy.

Complete answer:
Gold is a very rare occurring element that is bright yellow in colour with being highly ductile, malleable but least reactive in nature. Due to its lustre, shine, and economical value it is being used for the purpose of coin making, jewellery making, and also for art decoration from ancient times.
Now we can understand the reason why finding the purity of gold is so important.
But for this the answer is, gold’s purity is measured in carats.
The term carat basically tells us about the percentage of gold present in a piece of metal; it is measured on a 24 point scale.
24 carat defines that the piece of metal contains only pure gold or we can say that the piece is not adulterated with other metals.
Lower carat marking tells us that gold is present but with other metal, for instance, 18 carat or 18K gold contains 75 percent of pure gold with 25 percent of other metal being there(mostly copper and silver is used) or we can say that 18 parts out of 24 parts are made up of pure gold.

The carat marking for a piece of metal can be tested with the help of an acid test.

Note:
We must know that gold being one of the metals with the most value, it is important to detect its purity. Most of the time, gold is being alloyed with copper. Because copper metal has shine and lustre look similar to gold. Gold is being mixed with other metals to provide its structure; \[24K\] gold is of no use as it is very soft and will not be able to take any shape.