Ions and Their Formation

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What charge do Group 7A elements typically form?

-1 (correct)

Which of the following statements is true regarding Group 8A elements?

They form anions.

They are highly reactive.

They are unreactive. (correct)

They readily form cations.

Which ion would you expect to be more stable based on its electron configuration?

Cl-

S2- (correct)

Na+

Mg2+

How do metals on the left side of the periodic table tend to behave regarding electron loss?

Lose electrons easily to form cations. Signup and view all the answers

What is the naming convention for a cation formed from a main group metal?

Element name followed by 'ion'. Signup and view all the answers

What is the old naming convention for a cation with a smaller charge?

-ous Signup and view all the answers

Which ion is an example of a polyatomic ion?

SO4^2- Signup and view all the answers

What characterizes the ionization energy of metals compared to nonmetals?

Metals have lower ionization energy than nonmetals. Signup and view all the answers

What is the correct name for the compound NaCl?

Sodium Chloride Signup and view all the answers

Which of the following compounds is a Type I ionic compound?

MgCl2 Signup and view all the answers

What naming convention is used for Type II ionic compounds?

Roman numerals to specify cation charge Signup and view all the answers

Which statement about ionic compounds is correct?

Ionic compounds have a crystalline structure. Signup and view all the answers

How would you correctly name FeCl2 using modern conventions?

Iron(II) Chloride Signup and view all the answers

What property allows ionic compounds to conduct electricity when dissolved in water?

Free movement of ions Signup and view all the answers

What is the indication of a Type I ionic compound?

Has only main group cations with fixed charges Signup and view all the answers

When naming ionic compounds, which ion is listed first?

Cation Signup and view all the answers

What type of ion is formed when an atom loses one or more electrons?

A cation Signup and view all the answers

Which of the following statements is true regarding the properties of ionic compounds formed by alkali metals and halogens?

They are stable, white, crystalline solids. Signup and view all the answers

What is the electron configuration of alkali metals in their neutral state?

ns1 Signup and view all the answers

How is the charge of a cation typically expressed in its chemical symbol?

By placing the charge as a superscript Signup and view all the answers

Which ion formation results in a negatively charged ion?

Gaining an electron Signup and view all the answers

What common characteristic do ionic compounds generally share?

They conduct electricity in solution. Signup and view all the answers

Chlorine forms which type of ion when it gains an electron?

Anion Signup and view all the answers

What type of electron configuration do halogens have?

ns2np5 Signup and view all the answers

What indicates that a polyatomic ion has a charge?

It has a different total number of electrons compared to protons. Signup and view all the answers

What is the result of the ion-transfer reaction between sodium and chlorine?

A white solid, sodium chloride, is produced. Signup and view all the answers

Which of the following best represents how ionic bonds are formed?

Positive and negative ions are held together by ionic bonds. Signup and view all the answers

What is a formula unit in the context of ionic compounds?

The smallest neutral unit of an ionic compound. Signup and view all the answers

How should the formula for an ionic compound be written?

Cations are listed first and anions second with polyatomic ions in parentheses if needed. Signup and view all the answers

When ions have different charge numbers, what is necessary for a net charge of zero?

Unequal numbers of anions and cations must combine. Signup and view all the answers

Which of the following compounds forms from the reaction of calcium ions and nitrate ions?

Ca(NO3)2 Signup and view all the answers

What is the general relationship between the charges of cations and anions in an ionic compound?

The number of one type of ion must equal the charge of the other type. Signup and view all the answers

What is true about the melting and boiling points of ionic compounds?

They demonstrate very high melting and boiling points. Signup and view all the answers

Which of the following statements best describes the solubility of ionic compounds in water?

Ionic compounds dissolve if water's attraction to the ions is strong enough. Signup and view all the answers

What is the definition of an acid in terms of ion production in water?

A substance that provides H+ ions in water. Signup and view all the answers

What happens to the proton when an acid dissolves in water?

It attaches to a water molecule to form a hydronium ion. Signup and view all the answers

Which of the following represents a hydroxide anion?

OH– Signup and view all the answers

What distinguishes different acids from one another?

The number of H+ ions they can provide per molecule. Signup and view all the answers

Which base provides two OH– ions per formula unit?

Barium hydroxide (Ba(OH)2) Signup and view all the answers

Which of the following correctly identifies a property of bases?

They provide OH– ions in water. Signup and view all the answers

Study Notes

Ions

Ions are formed when a neutral atom gains or loses electrons.
Positively charged ions called cations result from the loss of one or more electrons.
Negatively charged ions called anions result from the gain of one or more electrons.
Alkali metals (Group 1A) form compounds with halogens (Group 7A). These compounds have high melting points, are stable, white crystalline solids, soluble in water, and conduct electricity when dissolved in water.

Ions and the Octet Rule

Alkali metals (Group 1A) have a single electron in their valence shell with an electron configuration of ns1.
By losing this electron, alkali metals become positively charged cations with a stable noble gas configuration.
Chlorine and other halogen atoms have 7 valence electrons, and an electron configuration of ns2np5.
By gaining an electron, halogens become negatively charged anions with a stable noble gas configuration.

Periodic Properties and Ion Formation

Ionization energy is the energy required to remove one electron from a single atom in the gaseous state.
Small ionization energy values indicate ease of losing electrons to form cations.
Electron affinity is the energy released on adding an electron to a single atom in the gaseous state.
Halogens have the largest electron affinity values and gain electrons most easily.
Alkali metals lose electrons most easily.
Noble gases neither lose nor gain electrons.

Naming Monoatomic Ions

Cations are named by identifying the metal, followed by the word ion.
Transition metals can form more than one type of cation. Two naming systems are employed for transition metals:
- Old System: The ion with the smaller charge is given the ending -ous, and the ion with the larger charge is given the ending -ic.
- New System: The charge on the ion is given as a roman numeral in parentheses right after the metal name.
Anions are named by replacing the ending of the element name with -ide followed by the word ion.

Polyatomic Ions

A polyatomic ion is an ion composed of more than one atom.
The atoms in polyatomic ions are held together by covalent bonds.
Polyatomic ions are charged because the total number of electrons differs from the total number of protons in the combined atoms.

Ionic Bonds

Ionic compounds form when metals and nonmetals react.
The opposite electrical charges of the ions attract each other, resulting in an ionic bond.
Ionic crystals are held together by ionic bonds.

Formulas of Ionic Compounds

All chemical compounds are neutral.
Ionic compounds are neutral because the total positive charge of the cations equals the total negative charge of the anions.
The chemical formula of an ionic compound expresses the ratio of anions and cations.
If ions have the same charge number, one of each is needed to achieve neutrality.
If ions have different charge numbers, unequal numbers of anions and cations must combine to have a net charge of zero.

Naming Ionic Compounds

Type I ionic compounds contain cations of main group elements and do not require specifying the charge on the cation.
Type II ionic compounds contain cations of transition metals that can exhibit more than one charge, requiring the specification of the charge on the cation.
- The charge on the cation can be indicated using either the old system (-ous, -ic) or the new system (roman numerals).

Properties of Ionic Compounds

Ionic compounds have very high melting and boiling points. This is due to the strong electrostatic forces between ions.
Many ionic compounds dissolve in water, but not all.
The solubility of ionic compounds depends on the relative strength of the attraction between the ions and the water molecules compared to the attraction between the ions themselves.

H+ and OH- Ions

Two of the most important ions are the hydrogen cation (H+) and the hydroxide anion (OH-), which are fundamental to the concepts of acids and bases.
An acid is a substance that provides H+ ions in water.
A base is a substance that provides OH- ions in water.
When an acid dissolves in water, the proton (H+) attaches to a water molecule to form a hydronium ion (H3O+).
Bases such as Sodium hydroxide (NaOH) and Potassium hydroxide (KOH) provide OH- ions in water along with the metal cation.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Explore the fascinating world of ions and their formation through electron transfer. Understand cations and anions, their properties, and how they relate to the octet rule and periodic properties. This quiz will test your knowledge on the behavior of alkali metals and halogens.