Elements that lie in the same column on the periodic table (called a group) have identical valance electron configurations and consequently behave in a similar fashion chemically. For instance, all the group 18 elements are inert, or noble gases. Element groups are either nonmetals or various subsets of metals, but there is no distinct line between the two types of elements. Metal elements are usually good conductors of both electricity and heat. Subsets are based on similar characteristics and chemical properties.
3 doctors agreed: A few hours: The typical dilating drops used at most eye doctors last about 4-6 hours. Some individuals are more sensitive to the effects and can remain dilated for up to a day. And if stronger dilating drops were used for a particular reason, their effects could last from 8 to 24 hours. ...Read more.
Get your eyes dilated. It is very common to have your eyes dilated during an eye exam. Dilating the eyes involves placing medicated eye drops in the eye with the purpose of dilating (widening) the pupils. This is done to look for diabetes, high blood pressure, macular degeneration, and glaucoma. Examine the health of your eyes. 2  To determine the health of your eye, your doctor will perform a slit light test. 3  Your chin will be placed in a chin rest that is connected to a slit light.