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Problem 1a
A charged particle moves between two electrically charged plates, as shown here.
(a) What is the sign of the electrical charge on the particle?
Problem 2a
The following diagram is a representation of 20 atoms of a fictitious element, which we will call nevadium (Nv). The red spheres are 293Nv, and the blue spheres are 295Nv. (a) Assuming that this sample is a statistically representative sample of the element, calculate the percent abundance of each element.
Problem 2b
The following diagram is a representation of 20 atoms of a fictitious element, which we will call nevadium (Nv). The red spheres are 293Nv, and the blue spheres are 295Nv. (b) If the mass of 293Nv is 293.15 u and that of 295Nv is 295.15 u, what is the atomic weight of Nv?
Problem 3a
Four of the boxes in the following periodic table are colored. Which of these are metals and which are nonmetals?
Problem 4a
Does the following drawing represent a neutral atom or an ion?
Problem 5
Which of the following diagrams most likely represents an ionic compound, and which represents a molecular one? Explain your choice.
- The most common charge associated with selenium is 2-. Indicate the chemical formulas you would expect for compounds formed between selenium and (a) barium (b) aluminum.
Problem 6
Problem 7
Five of the boxes in the following periodic table are colored. Predict the charge on the ion associated with each of these elements.
Problem 8
The following diagram represents an ionic compound in which the red spheres represent cations and the blue spheres represent anions. Which of the following formulas is consistent with the drawing? KBr, K2SO4, Ca1NO322, Fe21SO423.
Problem 10a
In the Millikan oil-drop experiment (see Figure 2.5), the tiny oil drops are observed through the viewing lens as rising, stationary, or falling, as shown here. (a) What causes their rate of fall to vary from their rate in the absence of an electric field?
Problem 11a
A 1.0-g sample of carbon dioxide (CO2) is fully decomposed into its elements, yielding 0.273 g of carbon and 0.727 g of oxygen. (a) What is the ratio of the mass of O to C?
Problem 11b
A 1.0-g sample of carbon dioxide (CO2) is fully decomposed into its elements, yielding 0.273 g of carbon and 0.727 g of oxygen. (b) If a sample of a different compound decomposes into 0.429 g of carbon and 0.571 g of oxygen, what is its ratio of the mass of O to C?
Problem 11c
A 1.0-g sample of carbon dioxide (CO2) is fully decomposed into its elements, yielding 0.273 g of carbon and 0.727 g of oxygen. If a sample of a different compound decomposes into 0.429 g of carbon and 0.571 g of oxygen, what is its ratio of the mass of O to C? (c) According to Dalton's atomic theory, what is the empirical formula of the second compound?
Problem 12a
Sodium reacts with oxygen in air to form two compounds: sodium oxide and sodium peroxide. In forming sodium oxide, 23.0 g of sodium combines with 8.0 g of hydrogen. In forming sodium peroxide, 23.0 g of sodium combines with 16.0 g of oxygen. (a) What are the mass ratios of oxygen in the two compounds?
Problem 12b
Sodium reacts with oxygen in air to form two compounds: sodium oxide and sodium peroxide. In forming sodium oxide, 23.0 g of sodium combines with 8.0 g of hydrogen. In forming sodium peroxide, 23.0 g of sodium combines with 16.0 g of oxygen. (b) What fundamental law does this experiment demonstrate?
Problem 13a1
A chemist finds that 30.82 g of nitrogen will react with 17.60, 35.20, 70.40, or 88.00 g of oxygen to form four different compounds. (a) Calculate the mass of oxygen per gram of nitrogen in each compound. 30.82 g N and 17.60 g O
Problem 13a4
A chemist finds that 30.82 g of nitrogen will react with 17.60, 35.20, 70.40, or 88.00 g of oxygen to form four different compounds. (a) Calculate the mass of oxygen per gram of nitrogen in each compound. 30.82 g N and 88.00 g O
Problem 13a2
A chemist finds that 30.82 g of nitrogen will react with 17.60, 35.20, 70.40, or 88.00 g of oxygen to form four different compounds. (a) Calculate the mass of oxygen per gram of nitrogen in each compound. 30.82 g N and 35.20 g O
Problem 13a3
A chemist finds that 30.82 g of nitrogen will react with 17.60, 35.20, 70.40, or 88.00 g of oxygen to form four different compounds. (a) Calculate the mass of oxygen per gram of nitrogen in each compound. 30.82 g N and 70.40 g O
Problem 13b
A chemist finds that 30.82 g of nitrogen will react with 17.60, 35.20, 70.40, or 88.00 g of oxygen to form four different compounds. (b) How do the numbers in part (a) support Dalton's atomic theory?
Problem 14a3
In a series of experiments, a chemist prepared three different compounds that contain only iodine and fluorine and determined the mass of each element in each compound: Compound Mass of Iodine (g) Mass of Fluorine (g) 1 4.75 3.56 2 7.64 3.43 3 9.41 9.86 (a) Calculate the mass of fluorine per gram of iodine in Compound 3.
Problem 14a1
In a series of experiments, a chemist prepared three different compounds that contain only iodine and fluorine and determined the mass of each element in each compound: Compound Mass of Iodine (g) Mass of Fluorine (g) 1 4.75 3.56 2 7.64 3.43 3 9.41 9.86 (a) Calculate the mass of fluorine per gram of iodine in Compound 1 and 2.
Problem 14b
In a series of experiments, a chemist prepared three different compounds that contain only iodine and fluorine and determined the mass of each element in each compound: Compound Mass of Iodine (g) Mass of Fluorine (g) 1 4.75 3.56 2 7.64 3.43 3 9.41 9.86 (b) How do the numbers in part (a) support the atomic theory?
- Discovering which of the three subatomic particles proved to be the most difficult—the proton, neutron, or electron? Why?
Problem 15
Problem 16a
An unknown particle is caused to move between two electrically charged plates, as illustrated in Figure 2.7. You hypothesize that the particle is a proton. (a) If your hypothesis is correct, would the particle be deflected in the same or opposite direction as the b rays?
Problem 16b
An unknown particle is caused to move between two electrically charged plates, as illustrated in Figure 2.7. You hypothesize that the particle is a proton. (b) Would it be deflected by a smaller or larger amount than the b rays?
- What fraction of the a particles in Rutherford's gold foil experiment are scattered at large angles? Assume the gold foil is two layers thick, as shown in Figure 2.9, and that the approximate diameters of a gold atom and its nucleus are 270 pm and 1.0 * 10–2 pm, respectively. Hint: Calculate the cross sectional area occupied by the nucleus as a fraction of that occupied by the atom. Assume that the gold nuclei in each layer are offset from each other.
Problem 17
Problem 18b
Millikan determined the charge on the electron by studying the static charges on oil drops falling in an electric field (Figure 2.5). A student carried out this experiment using several oil drops for her measurements and calculated the charges on the drops. She obtained the following data: Droplet Calculated Charge (C) A 1.60 * 10-19 B 3.15 * 10-19 C 4.81 * 10-19 D 6.31 * 10-19 (b) What conclusion can the student draw from these data regarding the charge of the electron?
Problem 18c
Millikan determined the charge on the electron by studying the static charges on oil drops falling in an electric field (Figure 2.5). A student carried out this experiment using several oil drops for her measurements and calculated the charges on the drops. She obtained the following data: Droplet Calculated Charge (C) A 1.60 * 10-19 B 3.15 * 10-19 C 4.81 * 10-19 D 6.31 * 10-19 (c) What value (and to how many significant figures) should she report for the electronic charge?
Problem 19c
The radius of an atom of tungsten (W) is about 2.10 Å. (c) If the atom is assumed to be a sphere, what is the volume in m3 of a single W atom?
