STANDARD A • MOST OF THE SLIDES FROM THIS POWER POINT PRESENTATION COMES FROM HOLT

CHEMISTRY. PLEASE DISREGARD THE CHAPTER NUMBERS.

• STANDARD A ASSESSEMENT WILL BE ON CHAPTER 2 OF THE IB CHEMISTRY BOOK

STANDARD A LG (a) SUBATOMIC PARTICLES Describe the proton,

neutron and electron in terms of location in atom, relative mass and charge and number of each in atoms

and ions as described by atomic number and atomic mass.

Standard A

LG (b) EARLY HISTORY OF ATOMIC MODEL: Know the contributions made by Dalton, Thomson, Millikan,

Rutherford and Chadwick as well as the experiments the lead to the discovery of the atom and its

subatomic particles.

Thomson’s experiment involveda cathode ray tube with a gas at lowpressure. The gas flowed from the negative end to the positive end of the tube. Because the gas consisted of electrons, it was repelled by the negative end of the magnet and attracted by the positive end of the magnet showing that an electron is negatively charged

THOMSON’S MODEL IS CALLED THE PLUM PUDDING MODEL

Thomson explained that the model was like plums representing the electrons in pudding represented as protons

Rutherford’s Gold Foil experiment involved shooting positively charged alpha particles through a thin piece of gold foil. He expected the alpha particles to pass straight through or get struck in the positive part. Instead most alpha particles passed straight through but a few were deflected or bounced straight back. This lead to the conclusion that an atom is mostly empty space but has a very small positively charged center (nucleus)

James Chadwick discovered the neutron.

The neutron was the last subatomic particle to be discovered because the neutron is neutrally charged. However because it has a mass almost equal to the proton, it became obvious that there had to be something else in the nucleus besides the proton

STANDARD ALG (c) ISOTOPES: Describe an isotope, compare the properties of the isotope of an element and deduce the symbol of an isotope given its mass number and atomic number.LG (d) RELATIVE MASS (AVERAGE ATOMIC MASS): Calculate the non integer relative mass and abundance of isotopes from given data.

LG (e) Discuss the use of radioisotopes

LG (f) MASS SPECTROMETER: Describe how the mass spectrometer is used to determine relative atomic masses

LG (g) ELECTROMAGNETIC SPECTRUM/ELECTRON CONFIGURATIONS: Describe the electromagnetic spectrum, explain how the lines in the emission spectrum of hydrogen are related to energy levels and distinguish between continuous and line spectrum.

LG (h) ELECTRON ARRANGEMENT: Deduce the electron arrangement for atoms and ions up to Z=20.