Lewis structure of water The Lewis structures, also called Lewis-dot diagrams or electron dot diagrams are pictures that show the bonding between a pair of electrons and the atoms of a molecule. Each dot represents one electron. Two dots side by side represent a lone pair of electrons. To show a bond between atoms, a line representing a pair of shared electrons is placed between the two atoms.
Or, maybe you're wondering just how old the tires are on the motorcycle you just bought. Here's how to tell: Look on the sidewall of the tire for the DOT symbol. Follow the line of text and numbers after the DOT symbol until you reach the end. If the tire was manufactured in the year 2000 or later, the last 4 digits give the age. The last 2 digits give the year and the preceding 2 digits give the week of manufacture.
Above: Photo of a Galvayne's groove in a 14 year old horse. When using teeth to try to determine the age of a horse older than 10 years, the Galvayne's groove is one of the indicators many horsemen will use. First appears at the gum line in horses about 10 years of age. 2  Each year, the groove will extend a little farther down the tooth. 3  It is expected to be about halfway down the tooth at 15 years of age, and all the way down (visible from top to bottom) at 20 years of age.