Chemistry Benchmark

How many atoms of carbon are included in one formula unit of the compound Na2C2O4? A. 2 B. 4 C. 6 D. 8

A. 2

Bismuth-211 is a radioisotope of bismuth that can decay by emission of an alpha particle. What atom is the product of alpha decay of bismuth-211? 211/83 Bi --> ? + 4/2 He A. 207/81 Tl B. 207/79 Au C. 209/79 Au D. 215/85 At

A. 207/81 Tl

How many electrons are represented in the Lewis dot structure for aluminum (Al)? A. 3 B. 8 C. 4 D. 13

A. 3

This table shows the naturally occurring isotopes of the element sulfur. Mass Actual Percent # Atomic Abundance Mass 32 31.97 95.02 33 32.97 0.75 34 33.97 4.21 36 35.97 0.02 What is the average atomic mass of sulfur? A. 32.06 amu B. 32.39 amu C. 33.75 amu D. 34.12 amu

A. 32.06 amu

Which set of elements has similar bonding properties? A. Cl, Br, and F B. K, Ca, and Sc C. Kr, Cl, and O D. Be, C, and O

A. Cl, Br, and F

What is the chemical formula of cobalt (II) hydroxide? A. Co(OH)2 B. Co2(OH) C. CoH2 D. Co2H2O

A. Co(OH)2

The ionization potential of an element is the amount of energy required to remove an electron from an isolated atom or molecule. According to the periodic table, which of the following indicates the correct decreasing order of ionization potential? A. Li>Na>K>Cs B. Na>K>Li>Cs C. Li>K>Na>Cs D. Cs>K>Na>Li

A. Li>Na>K>Cs

Which statement best describes an atom with an atomic number of 20? A. The atom has 20 protons. B. The atom has 20 neutrons. C. The sum of the number of protons and electrons is 20. D. The sum of the number of protons and neutrons is 20.

A. The atom has 20 protons.

Which statement best describes the characteristic shared by three isotopes of an element? A. The isotopes share the same number of protons. B. The isotopes share the same chemical stability. C. The isotopes have the same atomic mass. D. The isotopes have the same number of neutrons.

A. The isotopes share the same number of protons.

What type of radiation is given off when electrons drop from n = 4 to n = 2? A. Visible B. IR C. UV D. Gamma

A. Visible

Aluminum + Bromine --> A. aluminum bromide B. aluminum bromine C. aluminum (III) bromide D. aluminum (III) bromine

A. aluminum bromide

What is the IUPAC name of the compound whose formula is (NH4)3PO4? A. ammonium phosphate B. triammonium monophosphate C. triammonium phosphate D. ammonium phosphide

A. ammonium phosphate

The smallest particle of matter that can be identified as an element is called... A. an atom B. a proton C. an electron D. a molecule

A. an atom

Chlorine (Cl) is found in group 17 (7A) of the periodic table. Chlorine is commonly found combined with sodium (Na) to form table salt (NaCl). When chlorine reacts with sodium, how many electrons will a chlorine atom gain or lose? A. gain one electron B. lose one electron C. gain two electrons D. lose two electrons

A. gain one electron

Which set of elements have chemical properties similar to those of phosphorus? A. nitrogen, arsenic, and antimony B. carbon, selenium, and iodine C. silicon, sulfur, and germanium D. silicon, sulfur, and chlorine

A. nitrogen, arsenic, and antimony

Which of the following distinguishes the isotope uranium-238 from the isotope uranium-235? A. number of neutrons in the nucleus B. location on the periodic table C. amount of negative charge D. ability to form ions

A. number of neutrons in the nucleus

Which electron configuration shows the arrangement of electrons in an atom of bromine? A. (K)4s2 3d10 4p5 B. (Ar)4s2 3d10 4p5 C. 1s2 2s2 2p6 3s2 3p6 4s2 4d10 4p5 D. 1s2 2s2 3s2 4s2 2p6 3p6 4p5 4d10

B. (Ar)4s2 3d10 4p5

What is the charge of an iron atom with 24 electrons? A. -2 B. +2 C. -24 D. +24

B. +2

A neutral chlorine (Cl) atom contains 17 protons and 18 neutrons. How many electrons are there in a chlorine ion (Cl1-)? A. 17 B. 18 C. 34 D. 35

B. 18

What is the chemical formula of chromium(VI) sulfate? A. CrSO4 B. Cr(SO4)3 C. Cr2(SO4)3 D. Cr6SO4

B. Cr(SO4)3

Lewis dot structures are useful in determining the reactivity of an element. Based on the Lewis dot structures shown, which element is most likely to become a positive ion in reactions? A .. .O. .. B H. C .. :F. .. D .. .N. .

B. H.

Which statement explains why most of the mass of an atom is contained in the relatively small nucleus? A. Atoms are composed of less dense subunits than the nucleus. B. Protons and neutrons have more mass than electrons. C. The nucleus is located at the center of an atom. D. Atoms are composed of mostly empty space.

B. Protons and neutrons have more mass than electrons.

In which pair of elements are both metalloids? A. Sn and Sb B. Sb and Te C. Te and I D. I and Xe

B. Sb and Te

Group 17 (7A), the halogens, includes fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At). Which statement is most accurate concerning group 17 (7A) on the periodic table? A. They have 1 valence electron. B. They are extremely reactive. C. They are metals. D. They are inert.

B. They are extremely reactive.

Look at the Periodic Table of Elements. How are the elements arranged? A. by atomic mass B. by atomic numbers C. by element symbols D. by element name

B. by atomic numbers

Electron affinity increases from bottom to top in a family of nonmetal elements on the periodic table. What other pattern occurs from bottom to top of a nonmetal family based on this change in electron affinity? A. increase of the atomic number B. increase of chemical reactivity C. decrease of activation energy D. decrease of ionization energy

B. increase of chemical reactivity

When a formula unit of magnesium sulfide, MgS, is separated into magnesium and sulfur particles, the particles are called A. molecules B. ions C. isotopes D. compounds

B. ions

Which element has 2 electrons in the outermost energy level? A. cesium (Cs) B. magnesium (Mg) C. boron (B) D. argon (Ar)

B. magnesium (Mg)

Chromium is characterized by a very high melting point. Use the Periodic Table of the Elements to identify which of these elements most likely has a similar melting point. A. potassium B. manganese C. bromine D. krypton

B. manganese

Which event is an example of a chemical change? A. fog rising off a river B. wood burning in a fireplace C. ice cream melting in the sunshine D. grinding peppercorn into pepper flakes

B. wood burning in a fireplace

Beryllium has two valence electrons. When beryllium reacts with some other elements, it becomes an ion. What is the charge of a beryllium ion? A. -4 B. -2 C. +2 D. +4

C. +2

The element lanthanum has an isotope with an atomic mass of 138.9 amu and an abundance of 99.91%. A second isotope has an atomic mass of 137.9 amu and an abundance of 0.09%. What is the average atomic mass of lanthanum? A. 138.4 amu B. 138.8 amu C. 138.9 amu D. 139.0 amu

C. 138.9 amu

Which atom is the product of beta decay of xenon-140? 140/54 Xe --> ? + 0/-1 e A. 139/54 Xe B. 140/53 I C. 140/55 Cs D. 141/55 Cs

C. 140/55 Cs

The isotope 60/27 Co contains... A. 60 protons and 27 neutrons. B. 60 neutrons and 27 protons. C. 33 neutrons and 27 protons. D. 33 protons and 27 neutrons.

C. 33 neutrons and 27 protons.

A change in the number of neutrons in an atom will change the isotope. What will happen when the number of protons changes in an atom? A. Energy will be destroyed. B. Chemical bonding will occur. C. A new element will form. D. The atom will gain a charge.

C. A new element will form.

Which property allows carbon to form a variety of long-chain polymers? A. Carbon has six valence electrons used in multiple bonds. B. Carbon forms strong ionic bonds with different molecules. C. Carbon has four valence electrons, allowing for multiple bonds. D. Carbon forms both ionic and covalent bonds with other carbon atoms.

C. Carbon has four valence electrons, allowing for multiple bonds.

Going from left to right in the periodic table, the atomic radius decreases. Which of the following explains the atomic radii trend of elements across a period? A. There is an increase in the number of electron shells. B. There is a decrease in the number of electron shells. C. The attraction increases between the nucleus and the outer electrons. D. The attraction decreases between the nucleus and the outer electrons.

C. The attraction increases between the nucleus and the outer electrons.

Which properties are most affected by the number of electron orbitals around a non-metal atom? A. nuclear B. physical C. chemical D. radioactive

C. chemical

What is the IUPAC name for the compound N2O3? A. nitric oxide B. nitrous oxide C. dinitrogen trioxide D. trioxygen dinitride

C. dinitrogen trioxide

The electron configuration for an atom is (Xe)6s2 4f14 5d1. What element does this configuration represent... A. lanthanum B. hafnium C. lutetium D. yttrium

C. lutetium

What causes the emission spectrum of an element? A. movement of electrons from a lower energy state to a higher energy state B. movement of photons from a lower energy state to a higher energy state C. movement of electrons from a high energy state to a lower energy state D. movement of photons from a high energy state to a lower energy state

C. movement of electrons from a high energy state to a lower energy state

The mass of an element is the sum of the atomic number and the number of... A. electrons B. ions C. neutrons D. protons

C. neutrons

Which atom below would be most likely to form a compound with magnesium (Mg) in a ratio of one to one? A. nitrogen (N) B. calcium (Ca) C. oxygen (O) D. chlorine (Cl)

C. oxygen (O)

Elements are arranged on the Periodic Table of the Elements based on various properties such as electron configuration. An ion of a group 2 (2A) element will most likely have an electron configuration similar to that of a neutral atom from which group? A. 1 (1A) B. 3 (3B) C. 17 (7A) D. 18 (8A)

D. 18 (8A)

Which atom is the starting material of this nuclear decay process? ? --> 223/88 Ra + 0/-1 e A. 222/87 Fr B. 224/88 Ra C. 223/89 Ac D. 223/87 Fr

D. 223/87 Fr

A potassium (K) atom has 20 neutrons, 19 protons and 19 electrons. What is the atomic mass of potassium? A. 19 B. 20 C. 38 D. 39

D. 39

An atom of chromium has 24 protons, 28 neutrons, and 24 electrons. How many subatomic particles are in the nucleus of a chromium atom? A. 24 B. 28 C. 48 D. 52

D. 52

Chemical change can be identified by specific observations. Which would most likely indicate a chemical change? A. Solid carbon dioxide changes directly into carbon dioxide gas. B. Rock is slowly worn away by the action of wind and sand. C. A mineral is crushed into fine dust and mixed with water. D. A light green powder forms on the outside of a penny.

D. A light green powder forms on the outside of a penny.

Which statement best explains why metals are ductile and malleable? A. Delocalized electrons shared in metal atoms form weak bonds that are easy to break. B. The individual metallic atoms are stable and allow metals to be formed into various shapes. C. The positive and negative ions in the metal can easily break local bonds and then form new ones. D. Delocalized electrons in metallic bonds allow metal atoms to slide past one another instead of breaking the bonds.

D. Delocalized electrons in metallic bonds allow metal atoms to slide past one another instead of breaking the bonds.

The diagram below represents the Lewis dot structure for fluorine. . :F: .. Which statement best describes the Lewis dot structure for fluorine? A. Fluorine has a total of seven electrons. B. Flourine generally forms an ion by losing one electron. C. Flourine tends to form seven ionic bonds. D. Flourine has one electron available to form a covalent bond.

D. Flourine has one electron available to form a covalent bond.

Sodium, Na, is in the same group as... A. Ne B. Mg C. Ca D. K

D. K

Which of these statements is true about the parts that make up the atom? A. Protons are larger than neutrons. B. Electrons have a positive charge. C. Electrons are inside the nucleus. D. Neutrons have no charge.

D. Neutrons have no charge.

Mr. Martin adds vinegar to baking soda. Which shows that the vinegar and baking soda react chemically? A. The mass of the products increases. B. The substances form a solution. C. One of the reactants is a liquid. D. One of the products is a gas.

D. One of the products is a gas.

A bond is formed when an electron is transferred from a sodium atom to a chlorine atom. What happens to the sodium atom during this process? A. The mass of the atom increases. B. The atom becomes an isotope. C. The atomic number decreases. D. The atom becomes a positive ion.

D. The atom becomes a positive ion.

On the periodic table, why are all noble gases placed in column 18 (8A)? A. Noble gas elements have identical molar masses. B. Noble gases are all rarer than elements in other columns. C. The noble gases only chemically react with other noble gases. D. The valence electron configuration is similar in all noble gas elements.

D. The valence electron configuration is similar in all noble gas elements.

Which is an example of a chemical change? A. sand separated from water by filtering B. water evaporating from a puddle C. a rock being eroded by wind D. a nail rusting in water

D. a nail rusting in water

What property do metals exhibit as a result of having delocalized valence electrons? A. brittleness B. flammability C. low melting points D. electrical conductivity

D. electrical conductivity

A student has a homework assignment to identify the properties of an element based on its electron configuration. If the element has an electron configuration of 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p5 which of the following is most likely a property of this element? A. low ionization energy B. form ions with a 2- charge C. good electricity conductor D. forms salt with sodium (Na)

D. forms salt with sodium (Na)

What is the correct name for the compound whose formula is Fe2O3? A. iron oxide B. iron trioxide C. iron(II) oxide D. iron(III) oxide

D. iron(III) oxide

Elements on the right side of the periodic table differ from the elements on the left side in that the elements on the right side A. are solid at room temperature. B. are good electrical conductors. C. generally have very high densities. D. tend to form ions by gaining electrons.

D. tend to form ions by gaining electrons.