QUIZ 3

• What is the smallest unit that matter can be broken down into without

  releasing any electrically charged particles?

  Atom
• What is the combinations of two or more atoms which are held together by chemical bonds?

  Molecule
• Can an atom maintain stability all the time?

  No, it only achieves stability when its outermost electron shell is filled with electrons.
• Can a molecule maintain stability all the time?

  No, but it is considered stable under normal conditions.
• Who discovered the proton?

  Ernest Rutherford
• Who discovered the electron?

  J.J. Thomson
• Who discovered the neutron?

  James Chadwick
• What describes how electrons are distributed in its atomic orbitals?

  Electron configuration
• What is the selection of the orbitals for the electrons of an atom in its ground state follows an order?

  Aufbau Principle
• A law which states that if the chemical elements are listed in order of increasing atomic number, many of their properties go through cyclical changes, with elements of similar properties recurring at intervals?

  Periodic Law
• Who discovered the periodic law?

  Dmitri Mendeleev in 1871
• Who determined that periodicity depends on the atomic number rather than atomic weight?

  Henry Moseley in 1913
• Who presented his table several months after Mendeleev, but opposed Mendeleev's Periodic law?

  Lothar Meyer