Sometimes, two atoms of the same element have different numbers of neutrons. What is this known as

isotopes

Explanation Atoms of the same element sometimes have different forms just as we have plants of the same species having different varieties. These atoms usually have the same number of protons in their nuclei but different number of neutrons. They are referred to as isotopes

the circled areas are referred to   as sunspots.   the sunspots are cooler than the   surrounding area.

sunspots are temporary phenomena on the photosphere of the sun that appear visibly as dark spots compared to surrounding regions. they correspond to concentrations of magnetic field flux that inhibit convection and result in reduced surface temperature compared to the surrounding photosphere.

the wetland preservation movement began in the u.s. in earnest with the clean water act (cwa) of 1972. although not specifically written to protect wetlands, the cwa is comprised of a series of regulations designed to prevent pollutants from contaminating u.s. waters.