Please choose the correct ending to complete the given sentence: Computers and Electronics: [header] How to buy scrap gold [title] Find the purity level. [step] Look at the stamp on a piece of jewelry, for example, and this will indicate whether it is 10 , 14 or 24 karats (it is only measured up to 24 karats). If there is no stamp you or a jeweler can use nitric acid to find out the real karat of a piece.

Ending1: [substeps] Nitric acid is the number one variable in gold making. While it is not 100% reliable at making your carat, it is still relatively reliable for its purity and non-toxic quality. Ending2: [substeps] In most areas, the higher the purity level, the more pure the gold will be compared to scrap gold. For example, the metallic gold sold at ebay has 226 karats, which is less than abundant in zinc. Ending3: There are nitric acid kits available to purchase online at such sites as amazon in order to do this yourself. To convert karats to a percentage, divide the karat number by 24 and then multiply it by 100. Ending4: [substeps] Nitric acid, found in gold, is a sulfuric acid that coats and melts things. [title] Check the right grade for the quality.

Answer format: ending1/ending2/ending3/ending4