1.
The valence electrons in metals are only loosely held by the positively charged ions making them better conductors than nonmetals.
Correct Answer
A. True
Explanation
Metals have a unique atomic structure where the valence electrons are only loosely held by the positively charged ions. This loose hold allows the electrons to move freely within the metal lattice, making metals excellent conductors of electricity. On the other hand, nonmetals have a stronger hold on their valence electrons, restricting their movement and making them poor conductors. Therefore, the statement that metals are better conductors than nonmetals due to their loosely held valence electrons is true.
2.
An ion is formed when an atom
Correct Answer
A. Gains or loses an electron
Explanation
An ion is formed when an atom gains or loses an electron. This process occurs when an atom either gains an electron to become negatively charged (anion) or loses an electron to become positively charged (cation). The transfer of electrons allows the atom to achieve a stable electron configuration, similar to that of a noble gas. This gain or loss of electrons results in the formation of an ion.
3.
Ions that are made up of two or more atoms are called
Correct Answer
D. Polyatomic
Explanation
Polyatomic ions are ions that are made up of two or more atoms. These ions have a fixed charge and can either be positively charged (cations) or negatively charged (anions). Polyatomic ions are different from monatomic ions, which are made up of a single atom. Examples of polyatomic ions include ammonium (NH4+), sulfate (SO42-), and carbonate (CO32-).
4.
A negatively charged ion is called a cation
Correct Answer
B. False
Explanation
A negatively charged ion is actually called an anion, not a cation. Cations are ions that have a positive charge, while anions have a negative charge. Therefore, the statement given in the question is incorrect.
5.
A positively charged ion is called a cation
Correct Answer
A. True
Explanation
A positively charged ion is called a cation because when an atom loses one or more electrons, it becomes positively charged. This positive charge is balanced by the remaining negatively charged electrons, resulting in a net positive charge. Cations are attracted to negatively charged particles and are formed when atoms of metals lose electrons. Therefore, the statement "A positively charged ion is called a cation" is true.
6.
The attraction between two oppositely charged ions, positively charged metal and negatively charged nonmetal, is a called a(n)
Correct Answer
A. Ionic bond
Explanation
An ionic bond is formed when there is a strong attraction between two oppositely charged ions, specifically a positively charged metal ion and a negatively charged nonmetal ion. This bond occurs due to the transfer of electrons from the metal to the nonmetal. The resulting bond is characterized by the electrostatic attraction between the two ions, creating a stable and strong bond. Covalent bonds involve the sharing of electrons between atoms, while fixed and variable charged ions do not accurately describe the bond between a metal and nonmetal.
7.
When atoms combine together and have a full outer shell or energy level, the atoms have become
Correct Answer
A. Chemically stable
Explanation
When atoms combine together and have a full outer shell or energy level, they become chemically stable. This means that they have achieved a state where they are less likely to undergo chemical reactions or form bonds with other atoms. Having a full outer shell allows atoms to have a stable configuration similar to the noble gases, which are known for their low reactivity. Therefore, chemically stable is the correct answer in this context.
8.
Atoms that will always gain electrons to become stable are
Correct Answer
A. Elements in groups 1-13
Explanation
Atoms in groups 1-13 will always gain electrons to become stable because they have fewer electrons in their outermost energy level. By gaining electrons, they can achieve a full outer electron shell, which is the most stable configuration. Elements in groups 15-17, on the other hand, tend to gain or share electrons to achieve a full outer shell, while elements in group 18 already have a full outer shell and do not need to gain or lose electrons. Elements in group 14 can either gain or lose electrons depending on the specific element.
9.
Atoms that will always loose electrons to become stable are
Correct Answer
B. Elements in groups 15-17
Explanation
Elements in groups 15-17 will always lose electrons to become stable because they are nonmetals and have high electronegativity values. Nonmetals tend to gain or share electrons to achieve a stable electron configuration, so they have a strong tendency to gain electrons. Therefore, elements in groups 15-17 will lose electrons to achieve a stable octet configuration and become stable.
10.
Atoms that are considered stable just by their position on the periodic table are
Correct Answer
D. Elements in group 18
Explanation
The elements in group 18 of the periodic table are known as the noble gases. These elements have a full outer electron shell, making them highly stable and unreactive. Due to their stable electron configuration, noble gases do not easily form compounds with other elements. Therefore, atoms in group 18 are considered stable just by their position on the periodic table.
11.
Atoms that have the ability to form more than one ion are called
Correct Answer
B. Variable charged ions
Explanation
Variable charged ions are atoms that have the ability to form more than one ion. This means that they can gain or lose different numbers of electrons, resulting in ions with different charges. This ability to vary their charge makes them "variable charged ions." Fixed charged ions, on the other hand, refer to ions that always have the same charge, while chemically stable ions are ions that have a full outer electron shell and are therefore stable and less likely to form ions.
12.
What is the total number of atoms in H2SO4?
Correct Answer
C. 7
Explanation
The correct answer is 7 because H2SO4 consists of 2 hydrogen atoms (H), 1 sulfur atom (S), and 4 oxygen atoms (O). Adding these together gives a total of 7 atoms in H2SO4.
13.
What is the total number of atoms in Al2(SO4)3?
Correct Answer
D. 17
Explanation
The total number of atoms in Al2(SO4)3 can be calculated by adding up the individual atoms present in the compound. Al2(SO4)3 consists of 2 atoms of aluminum (Al), 3 atoms of sulfur (S), and 12 atoms of oxygen (O). Adding these together gives a total of 17 atoms.
14.
What is the charge of Sodium (Na)?
Correct Answer
A. +1
Explanation
The charge of Sodium (Na) is +1. This is because Sodium has one valence electron in its outermost shell, and it tends to lose this electron to achieve a stable electron configuration. By losing one electron, Sodium forms a positive ion with a charge of +1.
15.
All of the following are properties of an ionic compound accept for
Correct Answer
A. Low melting points
Explanation
Ionic compounds typically have high melting points due to the strong electrostatic forces of attraction between the positively and negatively charged ions. This is because ionic compounds are formed by the transfer of electrons from a metal to a nonmetal, resulting in the formation of ions with opposite charges. These strong forces require a significant amount of energy to break the bond and melt the compound. Therefore, the statement "low melting points" is not a property of an ionic compound.
16.
What is the charge of Selenium (Se)?
Correct Answer
B. -2
Explanation
The charge of Selenium (Se) is -2. This is because Selenium belongs to Group 16 of the periodic table, also known as the oxygen family. Elements in this group typically gain two electrons to achieve a stable electron configuration, forming an anion with a charge of -2. Therefore, the correct answer is -2.
17.
What is the charge of Aluminum (Al)?
Correct Answer
A. +3
Explanation
Aluminum (Al) has a charge of +3. This is because aluminum belongs to Group 13 of the periodic table, which means it has three valence electrons. In order to achieve a stable electron configuration, aluminum tends to lose these three electrons, resulting in a positive charge of +3.
18.
What is the charge of Krypton (Kr)?
Correct Answer
C. No charge (stable)
Explanation
Krypton (Kr) is a noble gas located in group 18 of the periodic table. Noble gases are known for their stability and lack of reactivity, which is due to their full outer electron shells. Krypton has a total of 36 electrons, with the electron configuration ending in 5s²5p⁶. Since the outermost shell is complete, krypton does not readily gain or lose electrons, resulting in no charge. This stability makes krypton an inert element, commonly used in lighting and laser applications.
19.
An element with 7 valence electrons is less reactive than an element with 8 valence electrons.
Correct Answer
B. False
Explanation
An element with 7 valence electrons is more reactive than an element with 8 valence electrons. This is because elements tend to react in order to achieve a stable electron configuration, typically by gaining or losing electrons to achieve a full outer shell. An element with 7 valence electrons only needs to gain one more electron to achieve a full outer shell, making it more likely to react. On the other hand, an element with 8 valence electrons already has a full outer shell and is less likely to react.
20.
Using the diagram below, determine what the ratio of sodium to nitrogen atoms will be when the two elements combine.
Correct Answer
B. 3:1
Explanation
The ratio of sodium to nitrogen atoms when the two elements combine is 3:1. This means that for every 3 sodium atoms, there will be 1 nitrogen atom present in the compound formed by their combination.
21.
Using the diagram below, identify which element can become stable by losing one valence electron.
Correct Answer
A. Sodium (Na)
Explanation
Sodium (Na) can become stable by losing one valence electron. Sodium is in Group 1 of the periodic table, which means it has one valence electron in its outermost energy level. By losing this one electron, sodium can achieve a full outer energy level, similar to the noble gas configuration of neon. This loss of one valence electron allows sodium to become stable and form a positive ion with a charge of +1.
22.
Using the diagram below, identify which element will be least likely to react with the other elements
Correct Answer
B. Argon (Ar)
Explanation
Argon (Ar) will be least likely to react with the other elements because it is a noble gas, which means it has a full outer electron shell and is therefore stable. Noble gases are generally unreactive and do not readily form compounds with other elements. Sodium (Na), Oxygen (O), and Chlorine (Cl) are all highly reactive elements that readily form compounds with other elements.
23.
Using the diagram below, identify the one atom that would react with two atoms of sodium to form a stable ionic compound.
Correct Answer
C. Oxygen (O)
Explanation
Oxygen (O) is the correct answer because it has two valence electrons, which allows it to form two ionic bonds with sodium (Na) atoms. Sodium has one valence electron, so it needs to gain one more electron to achieve a stable electron configuration. Oxygen can provide those two electrons, forming a stable ionic compound. Argon (Ar) is a noble gas and does not readily form compounds. Chlorine (Cl) has seven valence electrons and would only form one ionic bond with sodium.
24.
The chemical formula for a glucose molecule is C2H12O6 . The subscript represents the
Correct Answer
B. Number of atoms of each element in a glucose mlecule
Explanation
The subscript in a chemical formula represents the number of atoms of each element in a molecule. In the case of glucose (C6H12O6), the subscript 6 indicates that there are 6 carbon atoms, 12 hydrogen atoms, and 6 oxygen atoms in a glucose molecule.
25.
An ice cube (solid H2O) and a scoop of table salt (NaCl) are left outside on a warm sunny day. Which best explains why the the ice cube melts and the salt does not?
Correct Answer
A. The attractive forces between the molecules of H2O are weaker than those between ions in NaCl.
Explanation
The correct answer explains that the attractive forces between the molecules of H2O (water) are weaker than those between ions in NaCl (table salt). This means that the intermolecular forces holding the water molecules together are not as strong as the forces holding the ions in the salt together. As a result, the heat from the warm sunny day causes the weak intermolecular forces in the ice cube to break, causing it to melt into liquid water. On the other hand, the strong forces between the ions in the salt keep it intact, preventing it from melting.
26.
The ionic charge (oxidation number) of Fe in Fe2S3 is ___________.
Correct Answer
A. +3
Explanation
The ionic charge of Fe in Fe2S3 is +3. This is because Sulfur (S) has an oxidation number of -2, and there are three S atoms in Fe2S3, resulting in a total charge of -6. Since the compound is neutral, the total charge of Fe must be +6 to balance out the -6 charge from the S atoms. Since there are two Fe atoms in Fe2S3, each Fe atom must have a charge of +3 to give a total charge of +6.
27.
An atom that has gained an electron to become stable electron is a
Correct Answer
A. Negative ion
Explanation
When an atom gains an electron, it becomes negatively charged because the number of electrons now exceeds the number of protons. This results in an excess of negative charge, making the atom a negative ion.
28.
All elements in the Halogen group have a charge of
Correct Answer
C. -1
Explanation
All elements in the Halogen group have a charge of -1 because they have 7 valence electrons and tend to gain one electron to achieve a stable octet configuration. This results in a net charge of -1 for the halogens.
29.
When naming an ionic compound, the name of the nonmetal always comes first.
Correct Answer
B. False
Explanation
In the naming of an ionic compound, the name of the nonmetal does not always come first. The name of the metal usually comes first, followed by the name of the nonmetal. This is because in an ionic compound, the metal is the cation (positively charged ion) and the nonmetal is the anion (negatively charged ion). The cation is always named first in the compound's name. Therefore, the correct answer is false.
30.
An element in the Alkaline Earth Metal group would be most likely to form an ionic bond with an element in __________ .
Correct Answer
C. Group 16
Explanation
An element in the Alkaline Earth Metal group would be most likely to form an ionic bond with an element in Group 16. This is because elements in Group 16, also known as the Chalcogens, have a tendency to gain two electrons to achieve a stable electron configuration, while elements in the Alkaline Earth Metal group have a tendency to lose two electrons to achieve a stable configuration. Therefore, the transfer of two electrons from an Alkaline Earth Metal to an element in Group 16 would result in the formation of an ionic bond.
31.
The name Iron III indicates that the charge on the iron ion will be
Correct Answer
A. +3
Explanation
The name "Iron III" indicates that the charge on the iron ion will be +3. This is because the Roman numeral III represents the oxidation state of the iron ion, which is the charge that it carries. In this case, the iron ion has a positive charge of +3, indicating that it has lost three electrons.
32.
The name Copper II indicates that the charge on the copper ion will be
Correct Answer
A. +2
Explanation
The name Copper II indicates that the charge on the copper ion will be +2. In chemical nomenclature, Roman numerals are used to indicate the charge on transition metal ions with variable oxidation states. In this case, the Roman numeral II indicates that the copper ion has a +2 charge. This means that the copper atom has lost two electrons, resulting in a positively charged ion.
33.
The suffix added to the nonmetal when naming ionic compounds is
Correct Answer
B. -ide
Explanation
When naming ionic compounds, the suffix "-ide" is added to the nonmetal. This is because in an ionic compound, the nonmetal accepts electrons from the metal to form a negatively charged ion. The "-ide" suffix indicates that the nonmetal is in its most basic form, with a full complement of electrons. Therefore, "-ide" is the correct suffix to use when naming ionic compounds.
34.
When Iron +3 and Sulfur chemically combine to form and an ionic compound, the name of the compound would be ___________________
Correct Answer
C. Iron III Sulfide
Explanation
When Iron +3 and Sulfur chemically combine, they form an ionic compound. In this compound, Iron is in its +3 oxidation state, which is represented by the Roman numeral III. Sulfur is in its -2 oxidation state. Therefore, the correct name for this compound is Iron III Sulfide.