4 Written Questions

1. a theory proposed by John Dalton in 1808, based on numerous scientific experiments that marked the beginning of the development of modern atomic theory.
2. a neutral subatomic particle in an atom's nucleus that has a mass nearly equal to that of a proton.
3. the number after an element's name, representing the sum of its protons and neutrons.
4. a ray of radiation that originates from the cathode and travels to the anode of a cathode ray tube.

4 Multiple Choice Questions

1. the extremely small, positively charged, dense center of an atom that contains positively charged protons, neutral neutrons, and is surrounded by empty space through which one or more negatively charged electrons move.
   1. atom
   2. nucleus
   3. neutron
   4. proton
2. the weighted average mass of the isotopes of that element.
   1. atomic mass unit
   2. atomic mass
   3. atomic number
   4. atom
3. the number of protons in an atom.
   1. atomic mass unit
   2. mass number
   3. atomic number
   4. atomic mass
4. a negatively charged, fast-moving particle with an extremely small mass that is found in all forms of matter and moves through the empty space surrounding an atom's nucleus.
   1. proton
   2. neutron
   3. electron
   4. atom

4 True/False Questions

1. isotope → a subatomic particle in an atom's nucleus that has a positive charge of 1+.

   True        False

2. proton → a subatomic particle in an atom's nucleus that has a positive charge of 1+.

   True        False

3. atom → the smallest particle of an element that retains all the properties of that element; is electrically neutral, spherically shaped and composed of electrons, protons and neutrons.

   True        False

4. atomic mass unit → 1/12 the mass of a carbon-12 atom.

   True        False