NHCO3 is not a well-known chemical compound. It appears to be a combination of ammonia (NH3) and carbon dioxide (CO2), but it is not a recognized or stable compound in chemistry. If you meant sodium bicarbonate (NaHCO3), also known as baking soda, it is a common leavening agent used in baking and as an antacid.
NaHCO3 is chemically named as sodium hydrogen carbonate. However, scientifically, and commerically it is also known as sodium bi-carbonate It other name is 'baking powder'. as it is used in bakery to make dough rise.
Baking soda is the chemical sodium hydrogen carbonate The formula is NaHCO3 So 1 molecule of baking soda has 1 x sodium 1 x hydrogen 1 x carbon 3 x oxygen atoms in its compound. NB Baking soda is also known as 'Sodium bi-carbonate' Do not confuse with Sodium carbonate ( Na2CO3), which is known as washing soda, or soda crystals.