Which gas is called laughing gas?
ammonia
nitrous oxide
nitrogen dioxide
sodium oxide
Nitrous oxide (N2O), more commonly referred to as laughing gas, is used as a local sedation method, according to the California Dental Association (CDA).  Nitrous oxide is effective as a sedative because it relaxes patients with the pleasurable feelings it emits. Nitrous oxide's usefulness also stems from how quickly it works and that its effects are reversible. 
reach: rather globalchemistrymedicine
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