Six astronauts are still on the space station as part of a planned year-long stay in space, the longest tour of duty in the station's 15-year history.
The molecular formula of citric acid is C 6 H 8 O 7. The chemical formula for citric acid is best shown by a diagram of its complete structural formula. This shows how the atoms are arranged in the molecule. Citric acid has three carboxyl or-COOH groups and is triprotic in nature.
The compound that contains both covalent and ionic bonds is the compound of NH4Cl ( ammonium chloride). The Nitrogen atoms in combination with the Hydrogen atoms form the covalent bonds. The Ammonium ion (the cation) and Chlorine ion (the anion) form the ionic bonds of the polyatomic ionic combination.