ΔH2 = - δH1 δH2 = - 2 x δH1 δH2 = 2 x <span>δ</span>H1
B- Earth completes a full spin on its axis once every 24 hours.
<span>Nitric acid is often manufactured from the atmospheric gases nitrogen and oxygen, plus hydrogen prepared by reforming of natural gas, in a two-step process. In the first step, nitrogen and hydrogen react to form ammonia:
In the second step, ammonia and oxygen react to form nitric acid and water:</span>
A molecule that has a central atom surrounded by three single bond pairs and one unshared pair would have a trigonal pyramidal shape. The electon arrangement of this is called tetrahedral. It involves one atom located at the apex and at the corners are three atoms with a trigonal base. An example would be ammonia or NH3. Nitrogen has five valence electrons so that it needs to three more electrons to satisfy the octet rule and be stable. It would share electrons with the three nitrogen present. In order, to achieve the most stable geometry, the three atoms of hydrogen would attach with a bond angle of 109 degrees.
