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.
Eyes dilate for many reasons. They mainly dilate to control the amount of light that enters the eye. Pupils become smaller when the light is bright, and larger in the dark. Eye doctors dilate eyes to check for signs of disease. Eyes can also dilate as a result of an illness, or another condition or emotion. The circular and radial muscle of the iris control eye dilation. The radial muscle responds to dim light and will cause your pupil to become larger. The circular muscle reacts to bright light and causes the pupil to grow smaller.