The stability of atoms depends on whether or not their outer-most shell is filled with electrons. If the outer shell is filled, the atom is stable. Atoms with unfilled outer shells are unstable, and will usually form chemical bonds with other atoms to achieve stability.
Answer: Older age.
A personal or family history of cancer.
Using tobacco.
Obesity.
Alcohol.
Some types of viral infections, such as human papillomavirus (HPV)
Specific chemicals.
Exposure to radiation, including ultraviolet radiation from the sun.
Explanation:
<span>All of the populations of different species that occupy and are adapted to a given area are referred as a community.
In a community, there will be many populations of different species. Population is a group of individual in a certain area. The more species in the community, the more complex it is.</span>
Sixty-five million years ago, more than three-fourths of all plant and animal species living on Earth becameextinct<span>. This event is known as the </span>K-T<span> mass </span>extinctionbecause it occurred at the boundary between theCretaceous<span> (K) and Tertiary (T) time periods. The most famous group of animals to perish was the dinosaurs.
Hope this helps :)</span>