CNT-Books wants an affordable way to establish remote connections for its salespeople, who log on from customersites all over the country, and its three branch offices. The company’s main office is in Phoenix, Arizona, and its branch offices are in Los Angeles, California; Chicago, Illinois; and Orlando, Florida. Explain what kind of connections the salespeople and branch offices should use and what kinds of services should be installed on the main office’s network to keep communication costs to a minimum.

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.

the answer to this question is 3.

the seeing the electronic configuration we can say that the element is fluorine.

fluorine is the most electronegative element in the periodic table.

but by only seeing the configuration we cannot say about its reactivity because we don't know if its configuration after excitation or by addition of electrons.

but if not then, it is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions. as the most electronegative element, it is extremely reactive: almost all other elements, including some noble gases, form compounds with fluorine.