Because arteries and arterioles become less elastic as people age, they cannot relax as quickly during the rhythmic pumping of the heart. As a result, blood pressure increases more when the heart contracts (during systole)âsometimes above normalâthan it does in younger people. Abnormally high blood pressure during systole with normal blood pressure during diastole is very common among older people.
Then in 1897, Thompson discovered the first component part of the atom: the electron, a particle with a negative electric charge. Discovery of the Atom. By the 19th century, technology had advanced greatly and many elements had been discovered to work with.
William Ramsay. Winner of the 1904 Nobel Prize in Chemistry, Ramsay helped establish the noble gases as a new group in the periodic table. He first discovered argon and then helium, followed by the other noble gases. Home / Learn / Historical Biographies The Scottish chemist William Ramsay (1852â1916) is known for work that introduced a whole new group to the periodic table, variously called over time the inert, rare, or noble gases.