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.
Dilating drops cause vision to be blurred for a period of 4 to 8 hours and induce photophobia, lack of accommodation, glare, and decreased contrast threshold and high-contrast visual acuity. For elderly patients whose vision and mobility are already compromised, these visual changes can be dangerous.