Which of the following is not part of Daltons atomic theory? 1) Atoms of different elements combine in whole number quantities. 2) Atoms of different elements have diffenret masses. 3) An atom of one element can be chemically transformed into a differnet type of atom. 4) Matter is not created nor destroyed in a chemical reaction; the molecular arrangements are changed. 5) Atoms of a given element have the same mass.

Two compounds of iron and chlorine, A and B, contain 1.270 g and 1.904 g of chlorine, respectively, for each gram of iron. Show that these amounts are in the ratio 2 : 3. Is this consistent with the law of multiple proportions? Explain.

Constant Composition of Compounds Two samples of sugar are decomposed into their constituent elements. One sample of sugar produces 18.0 g carbon, 3.0 g hydrogen, and 24.0 g oxygen; the other sample produces 24.0 g carbon, 4.0 g hydrogen, and 32.0 g oxygen. Find the ratio of carbon to hydrogen and the ratio of oxygen to hydrogen for each of the samples, and show they are consistent with the law of constant composition.

Copper atoms. (a) What is the average mass of one copper atom? (b) Students in a college computer science class once sued the college because they were asked to calculate the cost of one atom and could not do it. But you are in a chemistry course, and you can do this. (See E. Felsenthal, Wall Street Journal, May 9, 1995.) If the cost of 2.0-mm diameter copper wire (99.9995% pure] is currently 41.70 for 7.0 g, what is the cost of one copper atom?

The element silver (Ag) has two naturally occurring isotopes: 109 Ag and 107Ag with a mass of 106.905 u. Silver consists of 51.82% 107Ag and has an average atomic mass of 107.868 u. Calculate the mass of 109Ag.

In the following drawing, the green spheres represent atoms of a certain element. The purple spheres represent atoms of another element. If the spheres of different elements touch, they are part of a single unit of a compound. The following chemical change represented by these spheres may violate one of the ideas of Dalton’s atomic theory. Which one?

Two elements, R and Q, combine to form two binary compounds. In the first compound, 14.0 g of R combines with 3.00 g of Q. In the second compound, 7.00 g of R combines with 4.50 g of Q. Show that these data are in accord with the law of multiple proportions. If the formula of the second compound is RQ, what is the formula of the first compound?

These questions concern the work of J. J. Thomson: From Thomson’s work, which particles do you think he would feel are most important in the formation of compounds (chemical changes) and why? Of the remaining two subatomic particles, which do you place second in importance for forming compounds and why? Come up with three models that explain Thomson’s findings and evaluate them. To be complete you should include Thomson’s findings.

Determine whether each statement that follows is true or false. a Dalton proposed that atoms of different elements always combine on a one-to-one basis. b According to Dalton, all oxygen atoms have the same diameter. c The mass of an electron is about the same as the mass of a proton. d There are subatomic particles in addition to the electron, proton, and neutron. e The mass of an atom is uniformly distributed throughout the atom. f Most of the particles fired into the gold foil in the Rutherford experiment were not deflected. g The masses of the proton and electron are equal but opposite in sign. h Isotopes of an element have different electrical charges. i The atomic number of an element is the number of particles in the nucleus of an atom of that element. j An oxygen 16 atom has the same number of protons as an oxygen17 atom. k The nuclei of nitrogen atoms have a different number of protons from the nuclei of any other element. l Neutral atoms of sulfur have a different number of electrons from neutral atoms of any other element. m Isotopes of different elements that exhibit the same mass number exhibit similar chemical behavior. n The mass number of carbon 12 atom is exactly 12g. o Periods are arranged vertically in the periodic table. p The atomic mass of the second element in the farthest right column of the periodic table is 10u. q Nb is the symbol of the element for which Z=41. r Elements in the same column of the periodic table have similar properties. s The element for which Z=38 is in both Group 2A/2 and the fifth period.

Each of the following statements is true, but Dalton might have had trouble explaining some of them with his atomic theory. Give explanations for the following statements. a. The space-filling models for ethyl alcohol and dimethyl ether are shown below. These two compounds have die same composition by mass (52% carbon, 13% hydrogen, and 35% oxygen), yet the two have different melting points, boiling points, and solubilities in water. b. Burning wood leaves an ash that is only a small fraction of the mass of the original wood. c. Atoms can be broken down into smaller particles. d. One sample of lithium hydride is 87.4% lithium by mass, while another sample of lithium hydride Ls 74.9% lithium by mass. However, the two samples have the same chemical properties.