Smartbook Ch. 2 Pt. II

Which of the following options correctly describe the mass number of an element? Select all that apply. a) In a neutral atom, the mass number equals the number of electrons in the atom. b) The mass number of a particular element never varies. c) The mass number is often written as a left superscript next to the atomic symbol. d) The mass number is given by the sum of the protons and neutrons in the nucleus. e) The mass number of an element is given the symbol A.

c) The mass number is often written as a left superscript next to the atomic symbol. d) The mass number is given by the sum of the protons and neutrons in the nucleus. e) The mass number of an element is given the symbol A.

The atomic mass unit _______. a) has units of grams b) is based on the mass of an electron c) is based on the mass of an atom of ^12(sub6)C d) is often abbreviated as amu e) is based on the mass of a hydrogen atom, which contains only 1 proton

c) is based on the mass of an atom of ^12(sub6)C d) is often abbreviated as amu

^59(sub27)Co isotope has ____ protons, ____ electrons, and ____ neutrons. a) 59; 59; 27 b) 27; 27; 32 c) 27; 27; 59 d) 59; 59; 32

b) 27; 27; 32

Which of the following statements correctly defines the atomic mass of an element? a) The sum of the protons and neutrons in an atom of the element b) The average of the masses of the natural isotopes of the element, according to their abundance c) The average number of neutrons in the natural isotopes of an element d) The sum of the masses of the isotopes of an element

b) The average of the masses of the natural isotopes of the element, according to their abundance

Match each component of the atom with the correct description. 1) Nucleus 2) Electron 3) Proton 4) Neutron a) Negatively charged particle b) Uncharged dense particle located in the center of the atom c) Positively charged particle found within the center of the atom d) Small region that contains almost all of the mass of an atom

d, a, c, b

An atom is composed of a very dense central _____ containing _____, which are positively charged, and neutrons, which have _____ electrical charge.

nucleus, protons, no

Each element 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.

protons, electrons

Which of the following statements correctly describe subatomic particles? Select all that apply. a) Protons are positively charged. b) The electrons are located outside the nucleus of an atom. c) The charge on a neutron is equal but opposite to the charge on a proton. d) A neutron is much heavier than a proton. e) The mass of an electron is significantly smaller than the mass of a proton.

a) Protons are positively charged. b) The electrons are located outside the nucleus of an atom. e) The mass of an electron is significantly smaller than the mass of a proton.

The atomic-mass _____ is used to define the atomic mass of elements that have very large variations in isotopic composition depending on their source.

interval

A particular isotope of an element is represented by the symbol ^36(sub17)Cl. The mass number of this isotope is equal to _____, and this number represents the total number of protons plus _____ in the nucleus. The atomic number of this isotope is equal to _____, and this number represents the number of _____ in the nucleus.

36, neutrons, 17, protons

Which of the following statements correctly describe the observations that led to the development of the nuclear model of the atom? Select all that apply. a) Millikan determined the charge on a proton. b) The discovery of cathode rays led to an understanding that the atom contains smaller particles. c) The conservation of mass led scientists to infer that atoms are indivisible. d) Rutherford determined that the main mass of the atom is concentrated in a central region. e) Thomson measured the mass/charge ratio for an electron.

b) The discovery of cathode rays led to an understanding that the atom contains smaller particles. d) Rutherford determined that the main mass of the atom is concentrated in a central region. e) Thomson measured the mass/charge ratio for an electron.

The atomic mass unit is defined as _______. a) 1/12 the mass of a carbon-12 atom b) the mass of one proton c) the mass of a hydrogen atom d) 1/12 the mass of an average carbon atom

a) 1/12 the mass of a carbon-12 atom

Which of the following options correctly describe the results of the experiments performed by Thomson and Millikan? Select all that apply. a) Millikan measured the electrical charge of oil droplets. b) It was found that cathode rays emitted by different substances differed in their composition. c) Thomson's work revealed the existence of the proton. d) Thomson studied the behavior of cathode rays. e) Millikan's work allowed the charge of the electron to be calculated.

a) Millikan measured the electrical charge of oil droplets. d) Thomson studied the behavior of cathode rays. e) Millikan's work allowed the charge of the electron to be calculated.

Which of the following statements correctly describe the atomic number of an element? Select all that apply. a) The atomic number is equal to the number of protons in the nucleus. b) The atomic number of an element varies depending on the number of electrons present. c) The atomic number is represented by the symbol A. d) The atomic number equals the number of neutrons present in the atom. e) Each element has its own unique atomic number.

a) The atomic number is equal to the number of protons in the nucleus. e) Each element has its own unique atomic number.

Which of the following correctly describe atomic structure? Select all that apply. a) The number of protons equals the number of electrons in a neutral atom. b) The nucleus comprises a very small fraction of the total volume of the atom. c) The number of neutrons in the nucleus equals the number of protons. d) The electrons comprise the nucleus of the atom. e) The protons and neutrons together comprise most of the mass of the atom.

a) The number of protons equals the number of electrons in a neutral atom. b) The nucleus comprises a very small fraction of the total volume of the atom. e) The protons and neutrons together comprise most of the mass of the atom.

Chlorine has two principal stable isotopes, ^35Cl (isotopic mass 34.9689) and ^37Cl (isotopic mass 36.9659). The atomic mass of Cl is 35.4527 amu. Which of the following options correctly describe these isotopes? a) ^35Cl has the greater abundance. b) The more abundant isotope comprises 75.774% of all stable Cl atoms c) ^35Cl comprises 34.97% of all stable Cl atoms d) The two isotopes are equally abundant.

a) ^35Cl has the greater abundance. b) The more abundant isotope comprises 75.774% of all stable Cl atoms

Isotopes are atoms of the same element that have the same _____ number but a different _____ number. This is because isotopes have the same number of protons but a different number of _____. a) atomic; mass; neutrons b) mass; atomic; neutrons c) atomic; mass; protons d) mass; atomic; electrons

a) atomic; mass; neutrons

Thomson's experiments with cathode rays determined that atoms contained even smaller particles called _____, which have a _____ charge. a) electrons; negative b) electrons; positive c) protons; negative d) protons; positive

a) electrons; negative

The _____ number of an atom is equal to the sum of the protons and _____ in the nucleus of the atom. a) mass; neutrons b) atomic; neutrons c) mass; electrons d) atomic; electrons

a) mass; neutrons

It is common to represent an element using its atomic symbol, which is an abbreviation based on its name. The _____ number, given by the symbol Z, is written as a left subscript while the _____ number, given by the symbol A, is written as a left superscript next to the atomic symbol.

atomic, mass

Dalton's atomic theory stated that matter consists of tiny indestructible particles called _____, which combine in definite ratios to form _____.

atoms, compounds

Mercury has seven stable isotopes. The most abundant is ^202(sub80)Hg, which has ____ protons, ____ electrons, and ____ neutrons. a) 80; 80; 42 b) 80; 80; 122 c) 202; 202; 80 d) 80; 122; 202 e) 202; 202; 122

b) 80; 80; 122

Which of the following options correctly describe Rutherford's experiment? Select all that apply. a) Rutherford's experiment established the electronic structure of the atom. b) An α particle was known at this time to be positively charged. c) The pathway followed by the α particles was tracked using a zinc-sulfide screen. d) This experiment used α particles to probe atomic structure.

b) An α particle was known at this time to be positively charged. c) The pathway followed by the α particles was tracked using a zinc-sulfide screen. d) This experiment used α particles to probe atomic structure.

Which of the following options correctly describe Dalton's atomic theory? Select all that apply. a) Atoms combine randomly to form a given compound. b) Atoms of the same element are identical. c) All matter consists of atoms. d) Atoms of one element can be converted into atoms of another element. e) Compounds result from the combination of a specific ratio of atoms of different elements.

b) Atoms of the same element are identical. c) All matter consists of atoms. e) Compounds result from the combination of a specific ratio of atoms of different elements.

Which of the following statements correctly describe isotopes? Select all that apply. a) Isotopes are atoms of the same element with the same mass. b) Isotopes have similar chemical properties. c) Isotopes have different numbers of protons. d) Isotopes have different numbers of neutrons. e) Isotopes of the same element have the same element symbols.

b) Isotopes have similar chemical properties. d) Isotopes have different numbers of neutrons. e) Isotopes of the same element have the same element symbols.

A particular isotope of an element is represented by the symbol ^15(sub7)N. Which of the following options correctly interpret this symbol? Select all that apply. a) The element has 15 electrons. b) The element contains 7 protons in its nucleus. c) The atomic number of the element is 15. d) The element contains 8 neutrons in its nucleus.

b) The element contains 7 protons in its nucleus. d) The element contains 8 neutrons in its nucleus.

All isotopes of an element have nearly identical chemical behavior because chemical behavior is determined primarily by ______. a) the number of protons in the element b) the number of electrons in the element c) the mass of the element d) the color of the element

b) the number of electrons in the element

Each element can be represented by an atomic symbol with the format ^A(subZ)X. Match each component of this symbol with its correct meaning. 1) Z 2) A 3) X a) Mass number: the total number of protons and neutrons in the nucleus b) Atomic number: the number of protons in the nucleus c) Atomic symbol: the element symbol found in the periodic table

b, a, c

Match each of the following experiments/observations with the information it contributed to the nuclear model of the atom. 1) Thomson's experiments with cathode rays 2) Millikan's oil-drop experiments 3) Rutherford's gold-foil experiment a) The determination of the charge on a single electron b) The discovery that atoms can be divided into smaller particles c) The discovery of the nucleus of the atom

b, a, c

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% abundance). The average atomic mass of the element is equal to _____. a) 69.93 b) 70.13 c) 69.73 d) 139.85

c) 69.73

The atomic mass unit is a standardized unit defined as exactly 1/12 the mass of a(n) _____-12 atom. The atomic mass (weight) of any element is determined relative to this standard and is not a whole number, since it is a(n) _____ of the masses of its naturally occurring isotopes.

carbon, average

Mass is conserved in a chemical reaction. This observation is reflected in Dalton's postulate that atoms cannot be _____ or destroyed, or changed into other types of atoms. Since each type of atom has its own _____ atomic mass, the total mass cannot change in a chemical reaction.

created, specific

How does Dalton's atomic theory account for the fact that different samples of the same compound always contain a fixed mass percentage of its component elements? a) A particular group of elements always combines in the same ratio to form a compound. b) The ratio of the atoms in a given compound varies, but the total mass of the compound remains the same. c) All the atoms of a given compound have the same mass. d) A given compound always contains a fixed ratio of its component elements.

d) A given compound always contains a fixed ratio of its component elements.

Differences in isotopic abundance ratios have been found for some elements depending on their source. IUPAC has given these elements ______ values to reflect these variations. a) new atomic mass b) updated isotopic mass c) metastable weight d) atomic-mass interval

d) atomic-mass interval

All isotopes of an element have ______ chemical behavior. a) unpredictable b) very different c) somewhat similar d) nearly identical

d) nearly identical

Rutherford's famous experiment involved bombarding a piece of _____ foil with _____ particles, which were known to be heavy and positively charged. The pathway of these particles was tracked by allowing them to strike a zinc-sulfide screen after interacting with the foil.

gold, alpha