3. Ernest Rutherford Ernest Rutherford, 1st Baron Rutherford of Nelson OM, FRS (30 August 1871 – 19 October 1937) was a New Zealand-born British chemist and physicist who became known as the father of nuclear physics. [1] In early work he discovered the concept of radioactive half life, proved that radioactivity involved the transmutation of one chemical element to another, and also differentiated and named alpha and beta radiation. This work was done at McGill University in Canada. It is the basis for the Nobel Prize in Chemistry he was awarded in 1908 "for his investigations into the disintegration of the elements, and the chemistry of radioactive substances". [2]OMFRSNew ZealandBritishchemistphysicistnuclear physics [1]half lifeMcGill UniversityNobel Prize in Chemistry [2] Rutherford performed his most famous work after he had moved to the U.K. in 1907 and was already a Nobel laureate. In 1911, he postulated that atoms have their positive charge concentrated in a very small nucleus, [3] and thereby pioneered the Rutherford model, or planetary, model of the atom, through his discovery and interpretation of Rutherford scattering in his gold foil experiment. He is widely credited with first "splitting the atom" in 1917. [4] This led to the first experiment to split the nucleus in a controlled manner, performed by two students working under his direction, John Cockcroft and Ernest Walton, in 1932.nucleus [3]Rutherford modelatomRutherford scatteringgold foil experiment [4]John Cockcroft Ernest Walton

4. Biography Ernest Rutherford was the son of James Rutherford, a farmer, and his wife Martha Thompson, originally from Hornchurch, Essex, England. [5] James had emigrated to New Zealand from Perth, Scotland, "to raise a little flax and a lot of children". Ernest was born at Spring Grove (now Brightwater), near Nelson, New Zealand. His first name was mistakenly spelled Earnest when his birth was registered.HornchurchEssex [5]PerthBrightwaterNelson He studied at Havelock School and then Nelson College and won a scholarship to study at Canterbury College, University of New Zealand where he was president of the debating society, among other things. After gaining his BA, MA and BSc, and doing two years of research at the forefront of electrical technology, in 1895 Rutherford travelled to England for postgraduate study at the Cavendish Laboratory, University of Cambridge (1895–1898), and he briefly held the world record for the distance over which electromagnetic waves could be detected.Havelock SchoolNelson College scholarshipCanterbury CollegeUniversity of New Zealanddebating societyBAMABScCavendish LaboratoryUniversity of Cambridge

5. Ernest Rutherford (movie: 10 min.) Most particles passed through. So, atoms are mostly empty. Some positive  -particles deflected or bounced back! Thus, a “nucleus” is positive & holds most of an atom’s mass. Radioactiv e substance path of invisible  -particles  Rutherford shot alpha (  ) particles at gold foil. Lead block Zinc sulfide screen Thin gold foil

6. Atomic numbers, Mass numbers  There are 3 types of subatomic particles. We already know about electrons (e – ) & protons (p + ). Neutrons (n 0 ) were also shown to exist (1930s).  They have: no charge, a mass similar to protons  Elements are often symbolized with their mass number and atomic number E.g. Oxygen: O 16 8 These values are given on the periodic table. For now, round the mass # to a whole number. These numbers tell you a lot about atoms. # of protons = # of electrons = atomic number # of neutrons = mass number – atomic number Calculate # of e –, n 0, p + for Ca, Ar, and Br.

7. Isotopes and Radioisotopes  Atoms of the same element that have different numbers of neutrons are called isotopes.  Due to isotopes, mass #s are not round #s.  Li (6.9) is made up of both 6 Li and 7 Li.  Often, at least one isotope is unstable.  It breaks down, releasing radioactivity.  These types of isotopes are called radioisotopes Q- Sometimes an isotope is written without its atomic number - e.g. 35 S (or S-35). Why? Q- Draw B-R diagrams for the two Li isotopes. A- The atomic # of an element doesn’t change Although the number of neutrons can vary, atoms have definite numbers of protons.

8. Legacy Nuclear physics Rutherford's research, and work done under him as laboratory director, established the nuclear structure of the atom and the essential nature of radioactive decay. Rutherford's team also demonstrated artificially induced nuclear transmutation. He is known as the father of nuclear physics. Rutherford died too early to see Leo Szilard's idea of controlled nuclear chain reactions come into being. A speech of Rutherford's printed in the September 12, 1933 London paper The Times is reported by Szilard to have been his inspiration for thinking of the possiblity of a controlled nuclear chain reaction, in London, on the same day. Rutherford's speech, in part, read: nuclear transmutationLeo Szilardnuclear chain reactionsThe Timesnuclear chain reaction

9. Items named in honour of Rutherford's life and work Scientific discoveries the element rutherfordium, Rf, Z=104. (1997) [11]rutherfordium [11] Institutions Rutherford Appleton Laboratory, a scientific research laboratory near Abingdon, Oxfordshire, UK.Rutherford Appleton LaboratoryAbingdon Oxfordshire Rutherford College, a school in Auckland, New Zealand Rutherford CollegeAuckland Rutherford College, a college at the University of Kent in Canterbury, UK Rutherford CollegeUniversity of KentCanterbury the Rutherford Institute for Innovation at the University of Cambridge, UKUniversity of Cambridge Rutherford Intermediate School, Wanganui, New Zealand Buildings a building of the modern Cavendish Laboratory at the University of Cambridge, UKCavendish LaboratoryUniversity of Cambridge The Ernest Rutherford Physics Building at McGill University, Montreal, Canada [12]McGill UniversityMontreal [12] the physics and chemistry building at the University of Canterbury, New ZealandUniversity of Canterbury The Coupland Building at the University of Manchester where Rutherford worked was renamed The Rutherford Building in 2006.University of Manchester The Rutherford lecture theatre in the Schuster Laboratory at the University of ManchesterUniversity of Manchester Major streets Rutherford Close, a residential street in Abingdon, Oxfordshire, UK.Rutherford CloseAbingdonOxfordshire Lord Rutherford Road in Brightwater, New Zealand — his birthplace.Brightwater Rutherford Road in the biotech district of Carlsbad, California, USA.Carlsbad, California Rutherford Street in Nelson, New Zealand.

10. Scientific Research During the investigation of radioactivity he coined the terms alpha and beta in 1899 to describe the two distinct types of radiation emitted by thorium and uranium. These rays were differentiated on the basis of penetrating power. From 1900 to 1903 he was joined at McGill by the young Frederick Soddy (Nobel Prize in Chemistry, 1921) and they collaborated on research into the transmutation of elements. Rutherford had demonstrated that radioactivity was the spontaneous disintegration of atoms. He noticed that a sample of radioactive material invariably took the same amount of time for half the sample to decay—its "half-life"—and created a practical application using this constant rate of decay as a clock, which could then be used to help determine the age of the Earth, which turned out to be much older than most of the scientists at the time believed.radioactivityalphabetaradiationthoriumuraniumFrederick SoddyNobel Prize in Chemistrytransmutationelementsradioactivityatomshalf-lifeclockEarth In 1903, Rutherford realised that a type of radiation from radium discovered (but not named) by French chemist Paul Villard in 1900, must represent something different from alpha rays and beta rays, due to its very much greater penetrating power. Rutherford gave this third type of radiation its name also: the gamma ray.radiumPaul Villardgamma ray