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.
Rutherford reasoned that if Thomson's model was correct then the mass of the atom was spread out throughout the atom. Then, if he shot high velocity alpha particles (helium nuclei) at an atom then there would be very little to deflect the alpha particles.He decided to test this with a thin film of gold atoms.owever, it was not clear how these protons and electrons were arranged within the atom. J.J. Thomson suggested theplum pudding model. In this model the electrons and protons are uniformly mixed throughout the atom: Rutherford tested Thomson's hypothesis by devising his gold foil experiment.