Chapter 7 Chem: Practice Test

Atoms that have gained or lost electrons are called ions. When an atom gains electrons, it becomes negatively charged and is called an anion. On the other hand, when an atom loses electrons, it becomes positively charged and is called a cation. Therefore, the correct answer for the question is ions, as it encompasses both positively and negatively charged atoms.

Salts are examples of ionic compounds because they are formed when a metal atom donates electrons to a non-metal atom, resulting in the formation of positive and negative ions. These ions are held together by strong electrostatic forces, creating a crystal lattice structure. Salts typically have high melting and boiling points, are soluble in water, and conduct electricity when dissolved or molten. Therefore, it is correct to say that salts are examples of ionic compounds.

Group 1 elements, also known as alkali metals, have one valence electron in their outermost energy level. These elements have a strong tendency to lose this electron in chemical reactions, resulting in the formation of a 1+ charged ion. This is because losing one electron allows them to achieve a stable electron configuration similar to that of noble gases. Therefore, the statement is true.

This statement is true because noble gases have a stable electron configuration with a full outer shell. Other elements react in order to achieve this stable electron structure, either by gaining, losing, or sharing electrons. This process allows them to attain a more stable and lower energy state, similar to noble gases.

When we "criss-cross," it refers to the process of transferring electrons between atoms in ionic compounds. This process occurs to achieve a more stable charge distribution. By exchanging electrons, atoms can attain a full outer electron shell, which is the most stable configuration. This stability is achieved by one atom losing electrons (becoming positively charged) and another atom gaining those electrons (becoming negatively charged). The resulting ionic bond between the positively and negatively charged ions creates a more stable compound overall.

A chemical bond is a force that holds two atoms together. It is the attraction between the positively charged nucleus of one atom and the negatively charged electrons of another atom. This attraction allows atoms to form molecules and compounds, creating stability and allowing for the formation of various substances. Chemical bonds can be classified into different types, such as covalent bonds, ionic bonds, and metallic bonds, depending on the sharing or transfer of electrons between atoms.

The given statement is incorrect. A positively charged ion is actually called a cation, not an anion. An anion refers to a negatively charged ion.

The crystal lattice of ionic compounds affects their melting and boiling points because the strong electrostatic forces between the oppositely charged ions in the lattice require a large amount of energy to break. This means that ionic compounds generally have high melting and boiling points.

The greater the lattice energy, the stronger the force of attraction is. This is because lattice energy represents the energy released when ions come together to form a solid lattice structure. A higher lattice energy indicates a stronger force of attraction between the ions, which means that it requires more energy to separate them. Therefore, the greater the lattice energy, the stronger the force of attraction between the ions.

A chemical bond refers to the attractive force between a positive nucleus and negative electrons, or positive and negative ions. This bond holds atoms together to form molecules and compounds. Therefore, the statement "A chemical bond is the attraction between a positive nucleus and negative electrons, or positive and negative ions" is true.

The energy required to lose an electron is known as ionization energy. This term refers to the amount of energy needed to remove an electron from an atom or ion in its ground state. Ionization energy is a fundamental concept in chemistry and is used to understand various properties of atoms and molecules, such as their reactivity and ability to form chemical bonds. It is an important factor in determining the behavior of elements in chemical reactions and plays a crucial role in fields like atomic physics and spectroscopy.

Sodium is an alkali metal with one valence electron. In order to achieve a stable electron configuration, it tends to lose this electron and form a positive ion. This is because losing one electron allows sodium to achieve a full outer shell, similar to the noble gas configuration. Therefore, the statement that a sodium atom tends to lose one electron when it reacts is true.

H+ is called a hydrogen ion because it is a positively charged hydrogen atom that has lost its electron. It is not called hydride because hydride refers to a negatively charged hydrogen ion, which has gained an extra electron. Therefore, the statement that H+ would be called a hydrogen ion and not hydride is true.

The lattice energy refers to the amount of energy needed to break apart the ions in an ionic compound and separate them. This process requires energy because the positive and negative ions are strongly attracted to each other due to their opposite charges. Therefore, the statement that the lattice energy is the energy required to separate the ions of an ionic compound is true.

Electron affinity refers to the amount of attraction an atom has for electrons. It measures the energy change that occurs when an atom gains an electron to form a negative ion (anion). Therefore, the correct answer is electrons, as electron affinity specifically relates to the attraction an atom has for electrons.

Cesium bromide is the correct answer because CsBr is the chemical formula for cesium bromide. Cesium is a chemical element with the symbol Cs and bromide is a compound containing the bromine ion. Therefore, CsBr represents the combination of cesium and bromine ions, forming cesium bromide.

Polyatomic ions are ions that are composed of more than one atom. These ions are formed when a group of atoms gain or lose electrons to achieve a stable electron configuration. They are held together by covalent bonds and carry a net charge due to the gain or loss of electrons. Examples of polyatomic ions include sulfate (SO4^2-), nitrate (NO3^-), and ammonium (NH4^+).

A formula unit (chemical formula for an ionic compound) is always neutral because ionic compounds are formed by the transfer of electrons between atoms, resulting in the formation of ions with opposite charges. The positive and negative charges of the ions cancel each other out, leading to a neutral overall charge for the formula unit.

The statement is true because the number of valence electrons determines an atom's ability to form bonds with other atoms. Atoms with fewer valence electrons tend to be more reactive because they are more likely to gain or lose electrons to achieve a full outer electron shell. On the other hand, atoms with a full outer electron shell tend to be less reactive because they are already stable and do not readily form bonds. Therefore, the number of valence electrons directly influences the reactivity of an atom.

Large numbers of positive ions and negative ions exist together in a ratio determined by the number of electrons transferred from the metal atom to the nonmetal atom. These ions are packed in a regular, repeating pattern that balances the forces of attraction and repulsion between the ions. This regular, repeated pattern in a 3-dimensional geometric arrangement is known as a crystal lattice.

Metals are cations because they tend to lose electrons and form positive ions. Nonmetals, on the other hand, are anions because they tend to gain electrons and form negative ions. This is due to the difference in electronegativity between metals and nonmetals, which determines their ability to attract and gain or lose electrons.

A Cl - ion is an example of an anion, not a cation. Cations are ions with a positive charge, while anions have a negative charge. In the case of a Cl - ion, the negative charge indicates that it is an anion. Therefore, the statement is false.

Ions with larger charges have a stronger attraction to each other, leading to a higher lattice energy. This is because the larger charge creates a stronger electrostatic force between the ions, causing them to be tightly held together in the crystal lattice. In contrast, ions with smaller charges have a weaker attraction and therefore a lower lattice energy. This is why ions with larger charges tend to produce a more negative lattice energy than ions with smaller charges.

Ionic compounds that are liquid conduct electricity because of delocalized electrons. In ionic compounds, electrons are transferred from one atom to another, creating positive and negative ions. In the liquid state, these ions are free to move and carry an electric charge. Delocalized electrons refer to the electrons that are not localized around a specific atom but are instead spread out over the entire compound. These delocalized electrons facilitate the flow of electric current in the liquid ionic compound, allowing it to conduct electricity.

A metallic bond is formed when metallic cations attract and share delocalized electrons. In a metallic bond, the outer electrons of metal atoms are free to move throughout the metal lattice, creating a "sea" of electrons. The positive metal cations are attracted to this electron sea, resulting in the formation of a metallic bond. This type of bond is responsible for the unique properties of metals, such as high electrical and thermal conductivity, malleability, and ductility.

The charge of a monoatomic ion is determined by the number of electrons that are transferred from the atom to the ion. This charge is referred to as the oxidation number. The oxidation number indicates the degree of oxidation or reduction of an atom in a compound, and it helps in determining the overall charge of the ion. Therefore, the correct answer is oxidation number.

Ionic compounds are conductive only when they are in a liquid or aqueous state because in these states, the ions are free to move and carry an electric charge. In solid state, the ions are held in a rigid lattice structure and cannot move, resulting in the compound being non-conductive. Therefore, the statement "Ionic compounds are conductive only when a liquid/aqueous" is true.

The ending "ide" is commonly used in chemistry to indicate that a compound is an anion. Anions are negatively charged ions, and the "ide" ending is added to the root of the element name to denote this. For example, chloride, fluoride, and bromide are all examples of anions. Therefore, the statement that the ending "ide" is used to designate an anion is true.

An ionic bond is the electrostatic force that holds oppositely charged particles together in an ionic compound. In an ionic bond, one atom donates electrons to another atom, resulting in the formation of positively charged cations and negatively charged anions. These oppositely charged ions are attracted to each other, creating a strong bond between them. This type of bonding is typically seen between a metal and a non-metal, where the metal loses electrons to become a cation and the non-metal gains electrons to become an anion.

Ionic crystals typically have high melting and boiling points because of strong, attracted forces. Similarly, ionic crystals are nonmalleable when solid.

An electrolyte is an ionic compound that, when dissolved in water, dissociates into ions and allows the flow of electric current. This is because the ions in the solution are free to move and carry the electric charge. Therefore, an ionic compound whose aqueous solution conducts an electric current is known as an electrolyte.

The statement is false because N+ would actually be called a nitrogen ion, not nitride. Nitride refers to a compound that contains nitrogen and another element, while a nitrogen ion specifically refers to a nitrogen atom that has gained or lost electrons and therefore has a positive or negative charge.

The given ion, Mg^2+, represents a magnesium ion with a charge of +2. Monoatomic ions are formed from a single atom, and in this case, the magnesium ion is formed by the loss of two electrons from a magnesium atom. Therefore, the correct answer is monoatomic.

An oxyanion is a polyatomic ionic compound composed of an element, usually a nonmetal, bonded to one or more oxygen atoms. Oxyanions are formed when an element gains one or more electrons from oxygen atoms, resulting in a negative charge. These ions are commonly found in many compounds, such as sulfates (SO42-), nitrates (NO3-), and carbonates (CO32-).

A binary ionic compound is a type of ionic compound that consists of only two elements, one being a metal cation and the other being a nonmetal anion. In this type of compound, the metal cation forms a positive charge, while the nonmetal anion forms a negative charge. These charges attract each other, resulting in the formation of a stable compound. Therefore, the correct answer is "Binary Ionic Compound."

The conductivity of an ionic compound depends on the free-moving ability of electrons. In an ionic compound, electrons are transferred from the cation to the anion, creating a lattice structure. The ability of these electrons to move freely within the lattice determines the conductivity of the compound. If the electrons can move easily, the compound will have high conductivity, whereas if the electrons are not free to move, the compound will have low conductivity. Therefore, the free-moving ability of electrons is a key factor in determining the conductivity of an ionic compound.

When naming ions, a positive ion is called a cation, while a negative ion is given the suffix "ide." This is because cations are formed when an atom loses electrons and becomes positively charged, while anions are formed when an atom gains electrons and becomes negatively charged. Therefore, the statement is true.

In general, higher oxidation states involve the loss of more electrons, resulting in a higher positive charge on the ion. This increased positive charge leads to stronger electrostatic attractions between the ions in the lattice, resulting in a higher lattice energy. Therefore, higher oxidation states are associated with higher lattice energy.

Substitutional alloys involve the replacement of atoms in a metallic crystal with other metals that have a similar atomic size. On the other hand, interstitial alloys have small holes in the metallic crystal that are filled with smaller atoms. This means that the atoms in interstitial alloys do not replace the original atoms, but rather fill the empty spaces between them.

Nonmetals actually form a stable outer electron configuration by gaining electrons and becoming anions, not by losing electrons. This is because nonmetals have a higher electronegativity and tend to attract electrons towards themselves. By gaining electrons, nonmetals can achieve a full outer electron shell, which is more stable. Therefore, the correct answer is False.

The smaller the ions are, the greater the lattice energy is because of interionic attraction due to there being a smaller distance between charges. Smaller ions have a higher charge density, meaning that the positive and negative charges are closer together. This results in stronger electrostatic forces of attraction between the ions, leading to a higher lattice energy.

Noble gases have high ionization energy because their outermost electron shells are completely filled, making it difficult to remove an electron. They also have low electron affinity because their electron shells are stable and do not readily accept additional electrons.

Lattice energy is the correct answer because it refers to the energy required to separate one mole of ions in an ionic compound. This energy is needed to overcome the attractive forces between the positively and negatively charged ions in the crystal lattice structure. Lattice energy is influenced by factors such as ion size, ion charge, and crystal structure, and it is an important property in determining the stability and properties of ionic compounds.

Steel is an example of an interstitial alloy because it is made by adding carbon atoms into iron. In an interstitial alloy, the smaller atoms of the alloying element fit into the spaces between the larger atoms of the base metal, resulting in a stronger and more durable material. This is different from a substitutional alloy where the atoms of the alloying element replace some of the atoms in the base metal's crystal lattice. Monoatomic does not accurately describe steel as it is made up of multiple atoms, not just one.

Ionic compounds are made up of ions, which are atoms or groups of atoms that have gained or lost electrons. Monoatomic ions are formed when a single atom gains or loses electrons, resulting in a positive or negative charge. These ions combine to form ionic compounds. Since the question states that ionic compounds always end in "ide," it implies that the compound is made up of a single atom, hence the correct answer is monoatomic.

The energy of an ionic compound is actually lower than that of the separate elements that formed it. This is because when ionic compounds form, energy is released in the process, making the overall energy of the compound lower than the energy of the individual elements.

Large ions tend to produce a less negative value for lattice energy than smaller ions do. This is because larger ions have a lower charge density, meaning that the positive charge is spread out over a larger area. As a result, the attraction between the positive and negative ions in the lattice is weaker, leading to a less negative value for lattice energy.

The correct answer is "Ite" will always have a superscript that is 1 greater than "ate." This is because when naming oxyanions, "ate" is used for the ion with the higher number of oxygen atoms, while "ite" is used for the ion with the lower number of oxygen atoms. The superscript represents the charge of the ion, and since "ite" has fewer oxygen atoms, it will have a lower charge than "ate." Therefore, the superscript for "ite" will be 1 greater than that of "ate."