science ch. 4 vocab.

7 Written Questions

1. idea that atoms are composed of negative and positive charges, arranged randomly, like plum pudding.
2. electrons that reside in the outermost shell of the atom. These electrons determine the chemical properties of an element.
3. the number of grams in 1 mole of an element or compound. This is equal to the atomic mass of an element or compound in grams.
4. exactly 1/12 the mass of a carbon-12 atom; roughly the mass of a proton or neutron.
5. a special version of an element that emits radiation.
6. an ancient Greek philosopher who believed that the universe was composed of small, indivisible particles called atoms.
7. various levels inside the atom where electrons can reside, based on their energy possession

6 Multiple Choice Questions

1. a shaded region in the electron cloud where an electron is most likely to reside, based on its position in the atom.
   1. Democritus
   2. AMU
   3. Orbital
   4. Photon
2. the number of protons in an atom, used to describe and element.
   1. Atomic mass
   2. AMU
   3. Molar mass
   4. Atomic number
3. British citizen born in New Zealand who proved the existence of the atomic nucleus.
   1. Valence electrons
   2. Ernest Rutherford
   3. Energy levels
   4. Atomic number
4. the weighted average mass (in AMU) of an element's atom in nature, roughly equal to the number of protons and neutrons that make up the most common versions of that element.
   1. Democritus
   2. Molar mass
   3. Atomic mass
   4. Atomic number
5. a version of an element, that may have any number of neutrons, but only one number of protons.
   1. Radioisotope
   2. Mole
   3. Isotope
   4. Photon
6. a rule that states that elements must combine to form compounds in integer ratio amounts
   1. Law of definite proportions
   2. Gold Foil Experiment
   3. Radioisotope
   4. Valence electrons

6 True/False Questions

1. Mole → exactly 6.02 x 1023 atoms or molecules of an element or compound. 1 unit of this is equal in mass to the atomic mass of an element or compound in grams.

   True        False

2. Photon → a single "particle" of light.

   True        False

3. Gold Foil Experiment → a special version of an element that emits radiation.

   True        False

4. Cathode ray tube → instrument consisting of positively and negatively charged plates, used by Thomson to infer the existence of subatomic electrons.

   True        False

5. Alpha particles → an ancient Greek philosopher who believed that the universe was composed of small, indivisible particles called atoms.

   True        False

6. Dalton's Atomic Theory → idea that atoms are composed of negative and positive charges, arranged randomly, like plum pudding.

   True        False