2 11. If each atom of element D has 3 mass units and each atom of element E has 5 mass units, a molecule composed of one atom each of D and E hasA. 2 mass units.B. 8 mass units.C. 15 mass units.D. 35 mass units.
3 2. If 6.0 g of element K combine with 17 g of element L, how many grams of element K combine with 85 g of element L? a. 17 g b. 23 g c. 30. g d. 91 g
4 21. According to the law of definite proportions, any two samples of KCl havea. the same mass.b. slightly different molecular structures.c. The same melting point.d. the same ratio of elements.
5 2. According to the law of conservation of mass, when sodium, hydrogen, and oxygen react to form a compound, the mass of the compound is ____ the sum of the masses of the individual elements. a. equal to b. greater than c. less than d. either greater than or less than
6 31. The principles of atomic theory recognized today were conceived by a. Avogadro. b. Bohr. c. Dalton. d. Rutherford.
7 2. Which of the following is not part of Dalton's atomic theory? a. Atoms cannot be divided, created, or destroyed.b. The number of protons in an atom is its atomic number.c. In chemical reactions, atoms are combined, separated, or rearranged.d. All matter is composed of extremely small particles called atoms.
8 4. 1. Experiments with cathode rays led to the discovery of the a. proton.b. nucleus.c. neutron.d. electron.
9 2. In Rutherford's experiments, most of the particles a. bounced back.b. passed through the foil.c. were absorbed by the foil.d. combined with the foil.
10 5. 1. Protons within a nucleus are attracted to each other by a. the nuclear force.b. opposite charges.c. their energy levels.d. electron repulsion.
11 2. The smallest unit of an element that can exist either alone or in combination with other such particles of the same or different elements is thea. electron.b. proton.c. neutron.d. atom.
12 Answers & Standards 1.1 – b – sc2 sc3 1.2 - c – sc2 sc3 2.1 - d – sc2 sc32.2 - a – sc2 sc33.1 – c – sc33.2 - b – sc34.1 - d – sc34.2 - b – sc35.1 - a – sc35.2 - d – sc3