Which element is needed for cellular respiration

Which of the following elements would you expect to have the lowest ionization energy value? fluorine, lithium, neon, nitrogen

Explain the relationship between forward and backward reactions in equilibrium, and predict how changing the amount of a reactant (creating a tension) will affect that relationship.

Apiece of copper has a temperature of 75.6 0c. when the metal is placed in 100.0 grams of water at 19.1 0c, the temperature rises by 5.5 0c. what is the mass of the metal?