Group5

- H20  John was born on September 6th, 1766 and died at the age of 77 on July 27th 1844. John was born a Quaker, near Cocker mouth in the Lake District. People believe that John started teaching at the Quaker school in Cumberland at the age of 12. To prove that his theory on the Atom model that it was in fact, correct, he made use of the common laboratory equipment which back in the 1800's consisted of various pieces of glassware, and manometers for the measurement of gas pressures. The year 1803 is when Dalton noted that oxygen and carbon combined make two compounds. He knew that each had their own particular weight ratio of oxygen to carbon. Also, for the same amount of carbon one had exactly twice as much oxygen. He then proposed the Law of Simple Multiple Proportions, this was later verified by the Swedish chemist, named Berzelius. He attempted to explain how and why the elements would combine with one another in fixed ratios and sometimes in multiples of those ratios. There wasn't much mention of another scientists helping with his atomic theory, but there's a chance that Joseph Priestly, Anotione Laoiser, and Joseph Louis Proust inspired, influenced or helped him with the process. > ===The Strengths and Weakness's:=== **Strengths: ** -electrons move fast through the atom. -electrons are trapped within the atom by a positively charged nucleus -electrons are negatively charged. **Weaknesses: ** -The atom failed to discover the nucleus, it contains protons that are positively charged particles.positively charged particles called protons -It also failed to discover that the nucleus, also contains neutron
 * John Dalton Atomic Model, By Nadja**
 * Five main points of the Dalton Atomic theory are... **
 * That Elements, are made of very very small particles called ...ATOMS.
 * Atoms that are a certain element are identical in size, mass and other properties.
 * Atoms of different elements, ﻿change in size, mass, and other properties.
 * Atoms of different elements combine in simple whole numbered ratios, that for.... chemical compounds.
 * Atoms cant be destroyed, subdivided or created.

John Dalton inspired and helped J.J Thomson with his atomic theory.

Refrences: Dalton Atomic Theory. (n.d.). //Royal Society of Chemistry, the largest organisation in Europe for advancing the chemical sciences//. Retrieved September 14, 2011, from []

Dalton's Atomic Theory. (n.d.). //Clackamas Community College Distance Learning//. Retrieved September 14, 2011, from __[|http://dl.clackamas.edu/ch104-04/dalton's.htm]__

__﻿__ Ernest Rutherford, By Gage Ernest Rutherford was born A ugust 30th 1871 and died 19 October 1937. he invented a detector for electromagnetic waves. He worked togather with Thomson on the behavour of the ions observed in gases which had been treated with x rays strengths: electrons move fast through the atom. electrons are trapped within the atom by a positively charged nucleus electrons are negatively charged. weaknesses: failed to discover the nucleus contains positively charged particles called protons failed to discover the nucleus also contains neutrons References: Google Images. (n.d.). //Google//. Retrieved September 14, 2011, from []

Above Is J.J. Thomson's version of the atomic model
Joseph John Thomson, who is better known as J.J. Thomson, was a British physicist who was born December 18th, 1856, in Ceetham Hill and died August 30th, 1940. He is known for first theorizing and offering experimental evidence that the atom is a divisible entity rather than the basic unit of matter, which was believed by most people at that time. He conducted a series of experiments with cathode rays at the end of the 19th century that led to his discovery of the electron. An electron is a negatively charged atomic particle with very little mass. Thomson was an independent person in terms of research until 1910 when he invited Francis Aston to come to Cambridge to become his research assistant. For exploring the electrical conductivity of various gases, Thomson received the Nobel Prize for Physics in 1906.

When Thomson was 14, he entered Owens College, where he first became interested in experimental physics, despite his first choice of career, being an engineer. Just a few years into his studies, Thomson’s father died, making it financially difficult for him to remain in the college. Through the efforts of his family and scholarships, he managed to remain in Owens College until 1976, when he transferred to Trinity College, Cambridge on a mathematics scholarship. He remained associated with Cambridge University for the rest of his life. He obtained a Bachelor’s Degree in mathematics in 1880.

He made his discovery of the electron in 1897, and later that year made it public. He discovered through his investigation of cathode rays. Thomson discovered that the rays could be deflected by an electric field (as well as a magnetic field, but that was already known at the time). Using that, he was able to find out the particles mass. This showed the cathode rays were made up of matter, but he found the particles to be 2000 times lighter than the lightest known atom, which is hydrogen. He concluded that the cathode rays were made up of very light negatively charged particles call corpuscles, or electrons.

Thomson’s next task was to consider how to incorporate the particle into the atom. Thomson was initially a strong believer in the plum-pudding atomic model, otherwise known as the Thomson atomic model. According to his view, each atom was a positively charged sphere with electrons scattered throughout it, sort of like bits of fruit in plum pudding. In 1911, a former student of Thomson, named Ernest Rutherford, came up with a version of the atomic model, in his view, which was much more likely.

__Strengths__
-Was good enough to explain many physical and chemical. -First atomic model to include electrons.