Old age refers to ages nearing or surpassing the life expectancy of human beings, and is thus the end of the human life cycle. Terms and euphemisms include old people , the elderly worldwide usage , OAPs British usage which stands for Old Age Pensioner , seniors American usage , senior citizens American usage , older adults in the social sciences  , and the elders in many cultures—including the cultures of aboriginal people. Elderly people often have limited regenerative abilities and are more susceptible to disease, syndromes, injuries and sickness than younger adults. The organic process of ageing is called senescence ,  the medical study of the aging process is called gerontology ,  and the study of diseases that afflict the elderly is called geriatrics. Old age is not a definite biological stage, as the chronological age denoted as "old age" varies culturally and historically.
Relative and Absolute Dating | Science Quiz - Quizizz
The principle stating that the oldest rocks occur on the bottom of an undisturbed rock sequence is known as superposition. Search for an answer or ask Weegy. There are no new answers. There are no comments. Add an answer or comment. Log in or sign up first.
Difference Between Relative Dating and Radiometric Dating
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All absolute isotopic ages are based on radioactive decay , a process whereby a specific atom or isotope is converted into another specific atom or isotope at a constant and known rate. Most elements exist in different atomic forms that are identical in their chemical properties but differ in the number of neutral particles—i. For a single element, these atoms are called isotopes. Because isotopes differ in mass , their relative abundance can be determined if the masses are separated in a mass spectrometer see below Use of mass spectrometers.