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.

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?

Which of the subatomic particles in an atom does not have a charge (and was therefore the last to be discovered)?

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?

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?

Which set of statements is true about Rutherford’s gold foil experiment?

i. This is the main experiment that showed that atoms have a dense nucleus.

ii. The data from the experiment showed that alpha particles scattered equally at all angles from the gold foil.

iii. Electrons were emitted from the gold atoms in straight lines.

a. i only

b. ii only

c. iii only

d. i and ii

e. i and iii

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?

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?

The radius of an atom of gold (Au) is about 1.35 Å. a. Express this distance in nanometers (nm) and in picometers (pm).

The radius of an atom of gold (Au) is about 1.35 Å. b. How many gold atoms would have to be lined up to span 1.0 mm?

The radius of an atom of gold (Au) is about 1.35 Å. c. If the atom is assumed to be a sphere, what is the volume in cm3 of a single Au atom?

An atom of rhodium (Rh) has a diameter of about 2.7×10−8 cm. a. What is the radius of a rhodium atom in angstroms (Å) and in meters (m)?

An atom of rhodium (Rh) has a diameter of about 2.7×10−8 cm. c. If you assume that the Rh atom is a sphere, what is the volume in m3 of a single atom?

Determine whether each of the following statements is true or false. a. The nucleus has most of the mass and comprises most of the volume of an atom.

Determine whether each of the following statements is true or false. b. Every atom of a given element has the same number of protons.

Determine whether each of the following statements is true or false. c. The number of electrons in an atom equals the number of neutrons in the atom.

Determine whether each of the following statements is true or false. d. The protons in the nucleus of the helium atom are held together by a force called the strong nuclear force.

Consider an atom of ¹⁰B. (a) How many protons, neutrons, and electrons does this atom contain?

Consider an atom of ¹⁰B. (b) What is the symbol of the atom obtained by adding one proton to ¹⁰B?

Consider an atom of ¹⁰B. (c) What is the symbol of the atom obtained by adding one neutron to ¹⁰B?

Consider an atom of ¹⁰B. (d) Are either of the atoms obtained in parts (b) and (c) isotopes of ¹⁰B? If so which one?

Consider an atom of ⁶³Cu. (a) How many protons, neutrons, and electrons does this atom contain?

Consider an atom of ⁶³Cu. b. What is the symbol of the ion obtained by removing two electrons from ⁶³Cu?

Consider an atom of ⁶³Cu. (c) What is the symbol for the isotope of ⁶³Cu that possesses 36 neutrons?

(a) Define atomic number and mass number.

(b) Which of these can vary without changing the identity of the element?

(a) Which two of the following are isotopes of the same element: ³¹₁₆X, ³¹₁₅X, ³²₁₆X?

(b) What is the identity of the element whose isotopes you have selected?

How many protons, neutrons, and electrons are in the following atoms? (a) ⁸⁴Kr (b) ²⁰⁰Hg (c) ⁷⁰Ga