<span>The number of electrons in an atom's outermost valence shell governs its bonding behavior.
In N</span>₂, three electrons are being shared by each nitrogen atom, making a total of 6 shared electrons.
In CCl₄, 4 electrons are being shared by each carbon atom and 1 electron is being shared by each chlorine atom
In SiO₂, 4 electrons are being shared by each silicon atom and 2 electrons are being shared by each oxygen atom.
In AlCl₃, 3 electrons are being shared by each aluminum atom and 1 electron is being shared by each Cl atom
In CaCl₂, 2 electrons are lost by the calcium atom and 1 electron is gained by each chlorine atom
In LiBr, 1 electron is lost by the lithium atom and 1 electron is gained by the bromine atom
Carbon dioxide and oxigen
Disadvantages of aluminum in building cars include:
On average, aluminum is more expensive than steel, as much as two to three times.
Aluminum is not easily welded. If a steel door or panel suffers a crack, often it cam be welded back together easily, primed and repainted so its difficult to tell any body work has been performed. This cannot be done with aluminum. Steel also can be bent and shaped as needed.
Body shops and even dealer service centers are currently equipped for steel work with technicians skilled in the art of welding and steel fabrication. The cost of switching over to an infra structure designed specifically for all-aluminum vehicles or mass production of aluminum vehicles and components would be high.
<span>Group 1 can be characterized as atoms that have 1 electron in their valence shell. This is valuable when dealing with these questions, because the loss or gain of valence electrons is what defines ionic relationships. When group 1 elements form ionic bonds with other atoms, they are extremely likely to lose their valence electron, since the nucleus has a weaker pull on it than, say, a chlorine atom has on its 7 valence electrons. The weaker pull between the nucleus and the valence electron of group 1 elements means that the radius is high, since the electron is more free to move with less pull on it. This also means that the first ionization energy is low, since it takes relatively little energy for that electron to be pulled away to another atom.</span>
