The answer Arguably, even a flashlight bulb is luminous, because it turns electricity (electrical energy) into light and shines it toward us. ... Photo: Luminous doesn't mean "glows in the dark": it means an object is giving off light it produces itself. Strictly speaking, that means the Sun (1) is luminous but the Moon (2) is not.
During heavy exercises we breathe faster to have more oxygen. In presence of high or sufficient amount of oxygen in our body we produce energy by breaking of pyruvate through aerobic pathway (the normal one). However in absence of required oxygen the body still can produce energy by opting the anaerobic pathway where lactate is being produced.
Thus the pH of body becomes acidic.
This excess H⁺ can be absorbed by bicarbonate ions.
There is one valence electron in each neutral H atom. Refer to a periodic table. H is one electron away from the closest noble gas: He. The H atoms need to achieve the noble gas configuration of He to be stable. For that, each H atom needs one more electron. There are two H atoms in an H₂ molecule. It will take 2 × 1 = 2 more electrons for both H atoms in each H₂ molecule to become stable.
Unlike ions, the H₂ molecule is neutral. There's no no extra electron for the H atoms. The two atoms need to share electrons with each other by forming chemical bonds. One chemical bond adds one electron to both bonding atoms. As a result, each bond will add two electrons to the molecule.
The H₂ molecule needs 2 extra electrons, which corresponds to 2 / 1 = 1 chemical bond.