Deck 5: Atoms, Molecules, Formulas, and Subatomic Particles

Question 1

Which of the following statements is not a part of atomic theory?

A) Chemical change involves a union, separation, or rearrangement of atoms.
B) A pure substance will have a varying relative number of atom types.
C) All matter is made up of atoms.
D) Atoms are considered indestructible during chemical change.

Answer 1

A pure substance will have a varying relative number of atom types.

Question 2

The diameters and masses of atoms are, respectively, on the order of ________.

A) 10^-11 m and 10^-11 g
B) 10^-23 m and 10^-10 g
C) 10^-24 m and 10^-10 g
D) 10^-10 m and 10^-23 g

Answer 2

10^-10 m and 10^-23 g

Question 3

Which one of the following statements about atoms is correct?

A) The proton is the smallest "piece" of an atom that can exist and still have the properties of the atom.
B) Free, isolated atoms are virtually never encountered in nature.
C) Atoms may be decomposed using physical change.
D) Two kinds of atoms may be present in a homoatomic molecule.

Answer 3

Free, isolated atoms are virtually never encountered in nature.

Question 4

Which one of the following statements about molecules is correct?

A) Some compounds have molecules as their basic structural unit.
B) For a molecular compound, the atom is the limit of chemical subdivision.
C) For a molecular compound, the atom is the limit of physical subdivision.
D) Molecules of compounds may be either heteroatomic or homoatomic.

Question 5

Which one of the following statements about heteroatomic molecules is incorrect?

A) Atoms in a heteroatomic molecule may be the same atom.
B) Upon chemical subdivision, heteroatomic molecules always yield two or more kinds of atoms.
C) Heteroatomic molecules do not maintain the properties of their constituent elements.
D) Elements are never heteroatomic molecules.

Question 6

Which statement about ionic compounds is incorrect?

A) Ionic compounds do not contain individual molecules.
B) Ionic compounds are charged, they are not electrically neutral.
C) Ionic compounds have an extended 3-dimensional assembly of ions.
D) Ionic compounds do not share the characteristics of the constituent elements.

Question 7

Which statement concerning the molecules depicted is incorrect?

A) The molecules in box I represent a pure substance.
B) The molecules in box III represent a mixture of elements.
C) The molecules in box II represent a compound composed of two different elements.
D) The molecules in box IV represents two different compounds and an element.

Question 8

In the formula C₄H₈O₂ ________.

A) there are 2 different elements
B) the ratio of carbon to hydrogen to oxygen atoms is 2:4:1
C) the percentage by mass of hydrogen is the same as oxygen
D) there is a total of 10 atoms

Question 9

In which of the following compounds does one molecule of the compound contain 3 elements and 8 atoms?

A) NaHCO₃
B) C₂H₇N
C) H₃AsO₄
D) POCl₃

Question 10

In which of the following pairs of formulas do the two members of the pair contain the same number of elements as well as the same number of atoms?

A) Co and CO
B) NaHCO₃ and NaHSO₄
C) SO₃ and SO₂
D) Cl₂CO and C₂HCl

Question 11

The total number of atoms present in 2 formula units of Ca(NO₃)₂ is ________.

A) 9
B) 18
C) 25
D) 30

Question 12

The total number of atoms present in five formula units of Sr(C₂H₃O₂)₂ is ________.

A) 65
B) 75
C) 18
D) 15

Question 13

How many atoms of each element are present in 3 formula units of (NH₄)₂HAsO₄?

A) 10 N atoms, 18 H atoms, 5 As atoms, 18 O atoms
B) 6 N atoms, 9 H atoms, 3 As atoms, 12 O atoms
C) 5 N atoms, 45 H atoms, 4 As atoms, 18 O atoms
D) 6 N atoms, 27 H atoms, 3 As atoms, 12 O atoms

Question 14

Which formula is correct for a molecule with 4 P atoms, and 10 O atoms?

A) 3 P₄O₁₀
B) 2(P₂O₃)₂
C) P₄O₁₀
D) 3 P₃O₆

Question 15

What is the total number of hydrogen atoms present in 6 formula units of Mg(C₂H₃O₂)₂?

A) 12
B) 6
C) 36
D) 24

Question 16

What is the total number of atoms in 5 formula units of Fe₂(C₂O₄)₃?

A) 55
B) 80
C) 100
D) 96

Question 17

What is the total number of O atoms in 6 formula units of hydroxyapetite, Ca₁₀(PO₄)₆(OH)₂, present in tooth enamel?

A) 156
B) 144
C) 106
D) 88

Question 18

Which of the following pairs of subatomic particles have charges of equal magnitude but opposite in sign?

A) electron and neutron
B) neutron and proton
C) proton and electron
D) proton and positron

Question 19

The nucleus of an atom ________.

A) contains all protons and electrons
B) is negatively charged because of the presence of electrons
C) is neutral since it contains only neutrons
D) is 1/10,000 of the size of the atom

Question 20

Atoms are neutral because ________.

A) all atoms contain neutrons
B) neutrons neutralize the (+) and (-) charges in the atom
C) the number of protons equals the number of electrons
D) equal numbers of protons and neutrons are present

Question 21

Which statement about an atom is false?

A) The nucleus is the center region of an atom.
B) The space occupied by the electrons is primarily empty.
C) The nucleus accounts for a small portion of the mass of an atom.
D) The volume occupied by electrons is referred to as an electron cloud.

Question 22

An atom contains 12 neutrons and 14 electrons. The mass number and the number of protons for this atom are, respectively, ________.

A) 14 and 26
B) 40 and 14
C) 26 and 14
D) 26 and 12

Question 23

All atoms of a given element may have different numbers of ________.

A) gamma rays
B) nucleons
C) neutrons
D) protons

Question 24

What are the number of protons, neutrons, and electrons in ?

A) 9 protons, 9 neutrons, and 10 electrons
B) 9 protons, 10 neutrons, and 9 electrons
C) 19 protons, 19 neutrons, and 19 electrons
D) 9 protons, 9 neutrons, and 19 electrons

Question 25

The number of electrons and neutrons in an atom of the type given below is ________. ²⁵Mg

A) 12 e, 13 n
B) 25 e, 12 n
C) 13 e, 25 n
D) 12 e, 12 n

Question 26

The number of neutrons in an atom is equal to:

A) the number of protons
B) atomic number - mass number
C) mass number - atomic number
D) the number of electrons

Question 27

Which of the following statements is incorrect?

A) All atoms of an element have the same atomic number.
B) All atoms of an element must have the same mass.
C) All atoms of an element have the same number of electrons.
D) Atoms of an element may have different numbers of neutrons.

Question 28

The total number of subatomic particles (protons, electrons, and neutrons) in an atom of ⁷⁵Ge is ________.

A) 86
B) 84
C) 107
D) 143

Question 29

The number of protons, electrons and neutrons in an atom of the type given below is ________.
^207Pb

A) 82 p, 125 e, 82 n
B) 82 p, 82 e, 125 n
C) 82 p, 125 e, 125 n
D) 125 p, 125 e, 164 n

Question 30

Choose the correct chemical symbol for an atom that contains 20 e^? and 24 n.

A)
B)
C)
D)

Question 31

Isotopes of a given element ________.

A) have the same mass number but different numbers of protons
B) have the same number of protons, but different mass numbers
C) have the same atomic number but different chemical properties
D) have the same mass number but different chemical properties

Question 32

The nucleus of atom A contains 20 protons and 20 neutrons and that of atom B contains 22 protons and 22 neutrons. It is true that atoms A and B are ________.

A) isotopes
B) isobars
C) both isotopes and isobars
D) neither isotopes nor isobars

Question 33

What is the mass number of a chromium isotope containing 28 neutrons?

A) 28
B) 24
C) 52
D) 76

Question 34

Iron is element number 26. This means that it has ________.

A) a mass number of 26
B) 26 neutrons in the nucleus
C) 26 protons inside its nucleus
D) 56 electrons

Question 35

What is the atomic number of an isobar of
In which there is an equal number of all three types of subatomic particles present?

A) 8
B) 9
C) 10
D) 11

Question 36

Which pair of neutrons and protons correspond to the isobars of Ar and Ca, which have a mass number of 40?

A) Ar: 18 protons and 22 neutronsCa: 20 protons and 20 neutrons
B) Ar: 18 protons and 22 neutronsCa: 20 protons and 22 neutrons
C) Ar: 20 protons and 20 neutronsCa: 18 protons and 22 neutrons
D) Ar: 22 protons and 18 neutronsCa: 20 protons and 20 neutrons

Question 37

Which of the following pairs of atoms contain the same number of neutrons?

A) ²⁷Al and ³¹P
B) ⁹Be and ⁷Li
C) ²²Ne and ²³Na
D) ⁵⁸Ni and ⁵⁸Fe

Question 38

Which of the following represents a pair of isotopes?

A) ¹⁴C, ¹⁴N
B) ¹H, ²H
C) ³²S, ³²S^-2
D) O₂, O₃

Question 39

Which of the following properties for the most abundant isotope of an element would not be possessed by the second most abundant isotope of the same element?

A) boiling point is 2403 °C
B) atomic number is 31
C) isotopic mass is 69.92 amu
D) reacts with chlorine to give the compound XCl₃

Question 40

Chlorine, which exists in nature in two isotopic forms, has an atomic mass of 35.5 amu. This means that ________.

A) all chlorine atoms have masses of 35.5 amu
B) 35.5 amu is the upper limit for the mass of a chlorine atom
C) ³⁵Cl and ³⁷Cl each constitute approximately 50% of all chlorine atoms
D) ³⁵Cl constitutes 75% of full chlorine atoms, ³⁷Cl represents 25%

Question 41

An isotope of which element is used as the standard for the relative mass scale for atoms?

A) carbon
B) oxygen
C) hydrogen
D) helium

Question 42

The isotopic mass for a particular isotope of gold is 196.9665 amu. The mass number for this gold isotope ________.

A) is 79
B) is 196
C) is 197
D) cannot be determined from the information given

Question 43

Three naturally occurring isotopes exist for the hypothetical element athenium. 2.50% of athenium atoms have a relative mass of 26.0 amu, 75.0% of athenium atoms have a relative mass of 27.0 amu, and 22.5% of athenium atoms have a relative mass of 28.0 amu. What is the atomic mass of athenium?

A) 26.8 amu
B) 27.0 amu
C) 28.0 amu
D) 27.2 amu

Question 44

Element A exists in three isotopic forms with masses of 21.0, 25.0 and 26.0 amu respectively. Element B also exists in three isotopic forms with masses of 22.0, 24.0 and 26.0 amu respectively. It is true that ________.

A) element A has a higher atomic mass than B
B) element B has a higher atomic mass than A
C) A and B have identical atomic masses since the sums of their isotopic masses are equal
D) you need the percentages of each isotope to determine their atomic masses

Question 45

What is the atomic mass of B if 19.9% of all B atoms have a mass of 10.01 amu and 80.1% have a mass of 11.01 amu?

A) 10.21 amu
B) 10.50 amu
C) 10.63 amu
D) 10.81 amu

Question 46

A hypothetical element, Rz, has two isotopes: ¹⁶⁹Rz = 168.94 amu and ¹⁷¹Rz = 170.98 amu. Eleven of every fifteen atoms of Rz found in nature exist as the ¹⁶⁹Rz isotope. What is the average atomic mass of the element Rz?

A) 169.48 amu
B) 168.95 amu
C) 170.56 amu
D) 171.01 amu

Question 47

Three naturally occurring isotopes of carbon exist: The atomic mass of carbon is 12.01 amu. Which of the three carbon isotopes is most abundant in nature?

A) carbon-12
B) carbon-13
C) carbon-14
D) All three occur with equal abundance.

Question 48

Which of the following was not a conclusion obtained from the gold foil-alpha particle scattering experiment?

A) An atom is mostly empty space.
B) An atom's nucleus is positively charged.
C) An atom's nucleus contains protons and neutrons.
D) Most of the mass of an atom is concentrated in its nucleus.

Question 49

Which is a conclusion about the atom's structure from Rutherford's gold foil-alpha particle experiments?

A) The electrons occupy most of the total volume of an atom
B) The mass of an atom is distributed uniformly throughout the atom.
C) All alpha particles are affected the same way by the atoms in the gold foil.
D) The positive charge of the atom is uniformly distributed throughout the atom.

Question 50

Match the molecules with the appropriate classification.

-

A) heteroatomic - polyatomic molecule
B) homoatomic - polyatomic molecule
C) heteroatomic - diatomic molecule
D) homoatomic - diatomic molecule

Question 51

Match the molecules with the appropriate classification.

-

A) heteroatomic - polyatomic molecule
B) homoatomic - polyatomic molecule
C) heteroatomic - diatomic molecule
D) homoatomic - diatomic molecule

Question 52

Match the molecules with the appropriate classification.

-

A) heteroatomic - polyatomic molecule
B) homoatomic - polyatomic molecule
C) heteroatomic - diatomic molecule
D) homoatomic - diatomic molecule

Question 53

Match the molecules with the appropriate classification.

-

A) heteroatomic - polyatomic molecule
B) homoatomic - polyatomic molecule
C) heteroatomic - diatomic molecule
D) homoatomic - diatomic molecule

Question 54

Match the molecules with the appropriate classification.

-

A) heteroatomic - polyatomic molecule
B) homoatomic - polyatomic molecule
C) heteroatomic - diatomic molecule
D) homoatomic - diatomic molecule

Question 55

Depicted are molecules that represent the following substances: NOCl, P₄, H₂S, IBr, and C₂H₂. Identify the substances present in each box.

Question 56

Depicted below are molecules that represent the following substances: OF₂, NH₃, H₂O₂, CH₂Cl₂, and Br₂. Identify the substances present in each box.

Question 57

Which of the terms heteroatomic, homoatomic, diatomic, triatomic, polyatomic, element and compound apply to each of the following molecules? More than one term may apply in a given situation.

Question 58

Fill in the blanks in the following sentences using words from the following response list:

Items in the response list may be used more than once or need not be used at all.
-The __________ of an atom contains protons and __________.

Question 59

Fill in the blanks in the following sentences using words from the following response list:

Items in the response list may be used more than once or need not be used at all.
-The identity of an atom (which element it is) is determined by the number of protons in its __________.

Question 60

Fill in the blanks in the following sentences using words from the following response list:

Items in the response list may be used more than once or need not be used at all.
-The atomic number gives the number of __________ and __________ in a neutral atom.

Question 61

Fill in the blanks in the following sentences using words from the following response list:

Items in the response list may be used more than once or need not be used at all.
-The mass number for an atom equals the sum of the __________ and __________ in the atom's nucleus.

Question 62

Fill in the blanks in the following sentences using words from the following response list:

Items in the response list may be used more than once or need not be used at all.
-The mass of a __________ (a neutral species) is many times greater than the mass of an electron and is approximately the same as the mass of a __________.

Question 63

Fill in the blanks in the following sentences using words from the following response list:

Items in the response list may be used more than once or need not be used at all.
-The __________ possesses a plus one charge, the __________ a minus one charge, and the __________ has no charge.

Question 64

Place in the blank the letter of the correct response in each horizontal row of choices.

-________ Number of elements in the compound Al₂SO₄

A) 3
B) 4
C) 5
D) 7

Question 65

Place in the blank the letter of the correct response in each horizontal row of choices.

-________ Number of atoms in the formula Ca(HCO₃)₂

A) 11
B) 15
C) 9
D) 10

Question 66

Place in the blank the letter of the correct response in each horizontal row of choices.

-________ Number of neutrons in

A) 15
B) 17
C) 20
D) 16

Question 67

Place in the blank the letter of the correct response in each horizontal row of choices.

-________ Number of electrons in

A) 20
B) 10
C) 30
D) 12

Question 68

Place in the blank the letter of the correct response in each horizontal row of choices.

-________ Number of subatomic particles in

A) 26
B) 8
C) 18
D) 22

Question 69

Place in the blank the letter of the correct response in each horizontal row of choices.

-________ Number of protons in

A) 7
B) 8
C) 14
D) 20

Question 70

Place in the blank the letter of the correct response in each horizontal row of choices.

-________ Identity of X in

A) Ti
B) Cr
C) I
D) Re

Question 71

Place in the blank the letter of the correct response in each horizontal row of choices.

-________ Mass number of a K isotope containing 21 neutrons

A) 19
B) 21
C) 40
D) 28

Question 72

Place in the blank the letter of the correct response in each horizontal row of choices.

-________ Mass number of an isotope containing 45 protons and 58 neutrons

A) 13
B) 45
C) 58
D) 103

Question 73

Place in the blank the letter of the correct response in each horizontal row of choices.

-________ An isobar of

A)
B)
C)
D)

Question 74

Place in the blank the letter of the correct response in each horizontal row of choices.

-________ An atom of Cu containing an equal number of protons, neutrons and electrons

A)
B)
C)
D )

Question 75

Place in the blank the letter of the correct response in each horizontal row of choices.

-________ Nuclear charge of

A) +10
B) +12
C) +11
D) +23

Question 76

For each description on the left select the correct atom from the response list on the right. Responses may be used more than once or need not be used at all.

-________ Has a mass number of 80

A)
B)
C)
D)

Question 77

For each description on the left select the correct atom from the response list on the right. Responses may be used more than once or need not be used at all.

-________ Has an equal number of protons and neutrons

A)
B)
C)
D)

Question 78

For each description on the left select the correct atom from the response list on the right. Responses may be used more than once or need not be used at all.

-________ Has more electrons than neutrons

A)
B)
C)
D)

Question 79

For each description on the left select the correct atom from the response list on the right. Responses may be used more than once or need not be used at all.

-________ Has more neutrons than electrons

A)
B)
C)
D)

Question 80

Fill in the chart below for each of the following isotopes. Be careful there may be more than one ion present.