8.1 Assessment
1. What is a chemical bond?
A chemical bond is the force that holds two atoms together.
2. Why do ions form?
An ion is an atom that has lost or gained an electron they form because neutral atoms become charged by the losing or gaining an electron this happens so that the ion of an element has a full outer shell.
3. What family of elements is relatively unreactive and why?
Elements of family group zero (sometimes also called as group eight) are known as Noble Gases. These are relatively unreactive because they have stable electronic configurations (means completed octet).
4. Describe the formation of both positive and negative ions.
Positive Ions: Form when an atom loses one or more valence electrons in order to attain a noble gas configuration.
Negative Ions: Form when an atom gains one or more electrons.
A chemical bond is the force that holds two atoms together.
2. Why do ions form?
An ion is an atom that has lost or gained an electron they form because neutral atoms become charged by the losing or gaining an electron this happens so that the ion of an element has a full outer shell.
3. What family of elements is relatively unreactive and why?
Elements of family group zero (sometimes also called as group eight) are known as Noble Gases. These are relatively unreactive because they have stable electronic configurations (means completed octet).
4. Describe the formation of both positive and negative ions.
Positive Ions: Form when an atom loses one or more valence electrons in order to attain a noble gas configuration.
Negative Ions: Form when an atom gains one or more electrons.
8.2 Assessment
12. What is an ionic bond?
The electrostatic force that holds oppositely charged particles together in an ionic compound.
13. How does an ionic bond form?
Ionic bonding occurs between a pair of atoms when one of the atoms gives up its valence electrons to the other. The result is that both atoms have filled shells.
14. List three physical properties associated with an ionic bond.
Melting point, boiling point and hardness are physical properties.
15. Describe the arrangement of ions in crystal lattice.
A crystal's ions are arranged in an orderly, repeating, geometric pattern.
16. What is lattice energy and how is it involved in an ionic bond?
The lattice energy of an ionic solid is a measure of the strength of bonds in that ionic compound.
The electrostatic force that holds oppositely charged particles together in an ionic compound.
13. How does an ionic bond form?
Ionic bonding occurs between a pair of atoms when one of the atoms gives up its valence electrons to the other. The result is that both atoms have filled shells.
14. List three physical properties associated with an ionic bond.
Melting point, boiling point and hardness are physical properties.
15. Describe the arrangement of ions in crystal lattice.
A crystal's ions are arranged in an orderly, repeating, geometric pattern.
16. What is lattice energy and how is it involved in an ionic bond?
The lattice energy of an ionic solid is a measure of the strength of bonds in that ionic compound.
8.3 Assessment
34. What is the difference between a monatomic ion and a polyatomic ion?
Monatomic ions are ions that consist of one atom. While polyatomic ions are ions of 2 or more atoms.
35. How do you determine the correct subscripts in a chemical formula?
When more than one atom of a specific element is found in a molecule, a subscript is used to indicate this in the chemical formula. For example, in water, H2O, there are two molecules of hydrogen and one molecule of oxygen.
36. How are metals named in an ionic compound? Nonmetals? Polyatomic ion?
The metal in an ionic compound is always the first in the formula, since they always have positive ions. Nonmetals are always negatively charged, so they come after the metals in the name and formula. Polyatomic ions are almost always negatively charged, so they are named after the metal.
37. What is an oxyanion and how is it named?
An oxyanion is a polyatomic ion composed of an element, usually a nonmetal, bonded to one or more oxygen atoms. It's name is based on the number of oxygen atoms in the ion.
Monatomic ions are ions that consist of one atom. While polyatomic ions are ions of 2 or more atoms.
35. How do you determine the correct subscripts in a chemical formula?
When more than one atom of a specific element is found in a molecule, a subscript is used to indicate this in the chemical formula. For example, in water, H2O, there are two molecules of hydrogen and one molecule of oxygen.
36. How are metals named in an ionic compound? Nonmetals? Polyatomic ion?
The metal in an ionic compound is always the first in the formula, since they always have positive ions. Nonmetals are always negatively charged, so they come after the metals in the name and formula. Polyatomic ions are almost always negatively charged, so they are named after the metal.
37. What is an oxyanion and how is it named?
An oxyanion is a polyatomic ion composed of an element, usually a nonmetal, bonded to one or more oxygen atoms. It's name is based on the number of oxygen atoms in the ion.
8.4 Assessment
40. What is a metallic bond?
A metallic bond is the attraction of a metallic cation for delocalized electrons.
41. Explain how conductivity of electricity and high melting point of metals are explained by metallic bonding.
Metals bond in a specific way. When they bond, a lattice (think of a 3-D cube) of positive nuclei is formed with a "sea" of floating electrons moving in between the nuclei. This creates a very strong bond between all of the nuclei.
42. What is an alloy?
An alloy is a mixture of elements that had metallic properties.
43. How does a substitutional alloy differ from an interstitial alloy?
Substitutional Alloy: Atoms of the solute take positions normally occupied by a solvent atom.
Interstitial Alloy: Solute atoms can occupy the "gaps" between the solvent atoms.interstitial alloy formed by wide range of metal with H,B,C,N etc
A metallic bond is the attraction of a metallic cation for delocalized electrons.
41. Explain how conductivity of electricity and high melting point of metals are explained by metallic bonding.
Metals bond in a specific way. When they bond, a lattice (think of a 3-D cube) of positive nuclei is formed with a "sea" of floating electrons moving in between the nuclei. This creates a very strong bond between all of the nuclei.
42. What is an alloy?
An alloy is a mixture of elements that had metallic properties.
43. How does a substitutional alloy differ from an interstitial alloy?
Substitutional Alloy: Atoms of the solute take positions normally occupied by a solvent atom.
Interstitial Alloy: Solute atoms can occupy the "gaps" between the solvent atoms.interstitial alloy formed by wide range of metal with H,B,C,N etc