The correct answer among the choices given is option A. Eustachian, Pharynx, Bronchi are structures that ensembles a tube. The Eustachian tube is a narrow passage from the pharynx to the middle ear. Pharynx is a passageway leading from the oral and nasal cavities to the larynx and the esophagus. Lastly, bronchi is an airway in the respiratory tract.
Molarity=moles/liter
molarity=43/0.64
molarity=67.19moles/litre
Protons
Explanation: the atomic number is the same as the number of protons
Answer:
4) transferred from the valence shell of one atom to the valence shell of another atom
Explanation:
Electrons are located outside of the nucleus which contains the protons and the neutrons.
For bonds to form, valence electrons located in the outermost shell electrons are involved. These are the valence electrons. These outer shell electrons can be shared or transferred between two combining atoms to form stable atoms.
In ionic bonds, the electrons are transferred from one specie to another. The atom that loses the electrons becomes positively charged and the receiving atom becomes negatively charged. This is the crux of ionic bonds.