Chapter 2

Which of the following statements about subatomic particles are correct? (select all that apply) A. Neutrons and protons are the only charges subatomic particles B. The charge on a proton is equal in magnitude and opposite in sign to that of an electron C. The mass of a proton is similar to that of a neutron D. The mass of a neutron is slightly greater than that of an electron

Which of the following statement correctly describes cathode rays? (select all that apply) A. A cathode ray consists of negatively charged particles B. The discovery of cathode rays showed that an atom can be broken down into smaller particles. C. The particles in a cathode ray are protons. D. Cathode rays are unaffected by magnetic or electrical fields.

Thompson's experiments with cathode rays determined that atoms contained even smaller particles called ____, which have a___ charge A. Protons, positive B. Electrons, positive C. Electrons, negative D. Protons, negative

Radioactivity is the spontaneous emission of ____ from an unstable nucleus.

Rutherford's famous experiment involved bombarding a thin piece of ____ foil with ___ particles, which are known to be heavy and positively charge. The pathway of these particles was tracked by allowing them to strike a fluorescent screen after interacting with the foil

Rutherford conducted a famous experiment in which alpha particles were fired at a piece of gold foil. A few alpha particles were reflected by a foil, leading Rutherford to the conclusion that the atom contains a small, very dense region in which most of the atom's _____ is concentrated. He called this central region the _____ of the atoms.

The positively charge particles in the nucleus of the atom is call a(n)_____. Its charge is equal in magnitude but opposite in sign to that of a(n)_____. A. Electron, proton B. Proton, neutron C. Neutron, electron D. Protons, electron

Which of the following observations suggested the existence of the neutron as a subatomic particle? (select all that apply) A. A sheet of beryllium bombarded by alpha particles produced a stream, of high-energy radiation with no electrical charge B. A sheet of gold foil bombarded by alpha particles caused the alpha particles to change direction C. The number of protons in the He nucleus could not account for its total mass D. Cathode rays could be emitted form different metal electrodes.

Which of the following correctly describe atomic structure? (Select all that apply) A. The nucleus comprises a very small fraction of the total volume of the atom B. The number of neutrons in the nucleus equals the number of protons. C. The protons and neutrons together comprise most of the mass of the atom D. The electrons comprise the nucleus of the atom E. The number of protons equals the number of electrons in the neutral atoms

Which of the following statements correctly describe Rutherford's experiment? Select all that apply A. The pathway followed by a alpha partial was tracked using a fluorescent zinc-sulfide screen B. A alpha particle was known at this time to be positively charged C. This experiment used alpha particles to probe atomic structure D. The deflection of the alpha particles showed that the nucleus of the atom was negatively charged E. Rutherford's experiment confirmed that the atom is a solid sphere

Rutherford's gold foil experiment was very important in developing the nuclear model of the atom. select all the statements that correctly describe the observations made and the implications of each for the atomic structure. Select all that apply A. The deflections of the Alpha particles indicated that the central core of the atoms is negatively charged B. A few alpha particles showed major deflections, indicating the presence of a dense central core wishing the atom C. All alpha particles passed through the foil, indicating that an atom is composed of scattered positive and negative charges D. Most alpha particles passed straight through the foil. implying that the atom consists largely of empty space.

According to the nuclear model, the atom is described as having a dense central _____, which contains the protons and _______. The _______ are distributed wishing the surrounding space

Which of the following options correctly describe isotopes? Select all that apply A. Isotopes of the same elements have the same element symbols B. Isotopes have different numbers of neutrons C. Isotopes are atoms of the same element with the same mass D. Isotopes have different numbers of protons E. Isotopes have similar chemical properties

Which of the following statements correctly describe atoms and elements? Select all that apply A. The term "atom" is another word for "element" B. An element cannot be divided into similar substances C. An atom can be divided into smaller particles that exhibit properties identical to those of the original atom D. An atom is considered a basic building block of matter

Each number has a unique number of ____, which is called the atomic number. For an electrically neutral atom, this number is also equal to the number of ____ present

The ____ number of an atom is equal to the sum of the protons and ____ in the nucleus of the atom. A. mass, electrons B. mass, neutrons C. atomic, neutrons D. atomic, electrons

How does the average atomic mass of an element compare to the mass number? A. The average atomic mass of an element is the same as its mass number B. The average atomic mass is the average mass of a mixture of isotopes, whereas each isotope has its own mass number C. The average atomic mass is equal to the mass number of the most abundant isotope of an element D. The average atomic mass includes the mass of the electrons, whereas the mass number depends only on the neutrons and the protons

An unknown element has two isotopes: one whose mass is 68.926 amu (60.00% abundance) and the other whose mass is 70.925 amu (40.00%). The average atomic mass of the element is equal to ____. A. 69.93 B. 69.73 C. 70.13 D. 139.85

What is the mass of 3.50 mol of Zn atoms? A. 18.7g B. 229g C. 0.0535g

Which if the following options give the correct number of moles and correct number of atoms in a3.54-g sample of copper (Cu)? Avogadro's number is 6.022x10^23. select both correct answers. A. 5.57x10^-2 mol of Cu B. 9.25x10^-26 atoms of Cu C. 2.25x10^2 mol of Cu D. 3.35x10^22 atoms of Cu

The ____ mass of a substance is the mass expressed in units of ____ per one mole for the substance

Which of the following statements correctly describe the relationship between the number of particles in a sample and its mass? Select all the apply A. The number of Ne atoms in a sample can be determined from the mass of the sample B. Two different samples of C-12 atoms that have the same mass must contain the same number of atoms C. Two samples may contain the same number of atoms but have different masses. D. A 10.00-g sample of Li atoms contains the same number if atoms as a 10.00-g sample of Ar atoms

The ______ is the SI unit that expresses the amount of substance. Specifically, it is defined as the amount of substance containing the same number of entities as the number of _____ in exactly 12 g of Carbon-12

t/f: A 16.00-g sample of oxygen atoms contains the same number of particles as a 4.003-g sample of He atoms

The number of entities in a mole (to 4 significant figures) is equal to _______x10^23 and is called _______ number.

Elements are arranged in the periodic table in order of increasing _______ number. The vertical column of the table are called ______ or families and the horizontal rows are called ______.