For the element chlorine to be "happy", it needs 8 valence electrons meaning it needs 8 electrons on its outer shell. So the answer would be chlorine because it has 7 valence electrons in the picture and it needs one more to be considered stable.
Number 2 lower entropy and higher entropy
Answer:
- <em><u>Mendeleev produced the first orderly arrangement of known elements.</u></em>
- <em><u>Mendeleev used patterns to predict undiscovered elements.</u></em>
Explanation:
- <u>Mendeleev produced the first orderly arrangement of known elements and used patterns to predict the undiscovered elements.</u>
Those two statments are true.
For the time being there were some 62 known elements. Before Medeleev some schemes to order part of the elements were proposed, but Medeleev showed the relationship between the atomic mass and the properties of the elements (supports second choice). This arrangement is known as the periodic table.
More importantly, Mendeleev predicted correctly the existance and properties of unknown elements, which is his major contribution: he left blanket spaces which where gradually filled when new elements where discovered (this supports the fourth choice).
The first modern chemistry book was written by Antoine Lavoisier (this discards first option).
Mendeleev ordered the elements by increasing mass number (this discards third choice), which was corrected later by the scientist Henry Moseley, who ordered the elements by increasing atomic number (number of protons).
Isotopes were not known by Mendeleev times, so this discards the last option.
A physical exothermic process
Answer:
See explanation
Explanation:
Whether a ligand is strong or weak highly depends on its position in the spectrochemical series. Ligands that are found towards the left hand side of the series are weak field ligands while ions that occur towards the right hand side of the series are strong field ligands. The spectrochemical series is an arrangement of ligands in order of increasing magnitude of crystal field splitting.
Most of the strong field ligands have strong pi bonds and are capable producing greater crystal field splitting.
NH3, an and NO2 are all strong field ligands hence they produce long wavelengths and lead to the formation of diamagnetic complexes.
