Which structure of the respiratory system allows for gas exchange? alveoli pharynx nose trachea

Alveoli

Explanation:

The respiratory system of the human beings consists of nose, pharynx, trachea and alveoli. The nose inhales air inside.

This air moves in towards lungs. The whole respiratory system is covered with mucous membrane which does not allows the entry of harmful microorganism and dust particles.

This filtered air reaches the alveoli and gaseous exchange takes place in between oxygen and carbon dioxide. The carbon dioxide is exhaled out and oxygen is transferred to cells of the body.

it is to be noted that an alpha particle is an helium nucleus. so it contains 2 protons 2 neutrons and has a mass number of 4. when alpha decay particles are ejected from the nucleus it gets transformed into an atom which has atomic number less than 2 and a mass number less than 4.

an equation that could represent alpha decay is radium 226 decay of alpha particle forms radon 222.

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