Question

investigation 3 experience 1: ionic bonds name a. engage: what happens when you mix an explosive metal with a poisonous gas? describe the reaction of pure potassium with water. describe the reaction of potassium chloride with water. what caused the potassium chloride to react with water the way it did? b. explore: ionic bond reading. as you read “ionic bonds”, answer the following questions: what is the octet rule? why are elements or compounds that fulfill the octet rule more stable? draw the electron dot structure for argon. what type of electrons are represented by the dots? what determines the type of ion an element will form? which types of elements form cations? why type form anions? draw the electron dot structure for the ion formed by fluorine. use a different color for the electron(s) the atom gained. what is an ionic bond? what types of elements form an ionic compound? draw and explain the electron dot structure for sodium chloride.

Explanation:

Step1: Reaction of explosive metal with poisonous gas

The reaction can vary greatly depending on the specific metal and gas. For example, some metals can react violently with certain gases to form new compounds, sometimes with explosive results due to the release of a large amount of energy. However, without specific metals and gases named here, a detailed reaction cannot be precisely described.

Step2: Reaction of pure potassium with water

Potassium is a very reactive metal. When it reacts with water, it undergoes a single - displacement reaction: $2K(s)+2H_2O(l)
ightarrow 2KOH(aq) + H_2(g)$. The reaction is highly exothermic and the hydrogen gas produced can ignite, causing a small explosion.

Step3: Reaction of potassium chloride with water

Potassium chloride ($KCl$) dissolves in water through a process called dissociation. $KCl(s)
ightarrow K^+(aq)+Cl^-(aq)$ in water. This is a physical - chemical process where the ionic bonds in $KCl$ are broken by the polar water molecules.

Step4: Cause of potassium chloride - water reaction

The polar nature of water molecules is the cause. Water is a polar molecule with a partial negative charge on the oxygen atom and partial positive charges on the hydrogen atoms. These polar water molecules surround the $K^+$ and $Cl^-$ ions in $KCl$, pulling them apart and allowing the salt to dissolve.

Step5: Octet Rule

The Octet Rule states that atoms tend to gain, lose, or share electrons in order to have a full outer shell of eight electrons (or two electrons for hydrogen and helium), which gives them a stable electron configuration similar to that of the noble gases.

Step6: Stability of elements/compounds fulfilling Octet Rule

Elements or compounds that fulfill the Octet Rule are more stable because a full outer shell of electrons represents a lower - energy state. Atoms with incomplete outer shells are more reactive as they seek to achieve a more stable electron configuration.

Step7: Electron - dot structure of argon

Argon has an atomic number of 18, and its electron configuration is $1s^22s^22p^63s^23p^6$. The electron - dot structure for argon has eight dots around the symbol Ar, representing its eight valence electrons. The dots represent valence electrons, which are the electrons in the outermost energy level and are involved in chemical bonding.

Step8: Determination of ion type

The number of valence electrons an element has determines the type of ion it will form. Metals tend to lose electrons to form cations, while non - metals tend to gain electrons to form anions.

Step9: Elements forming cations and anions

Metals form cations because they have relatively few valence electrons (usually 1 - 3) and it is easier for them to lose these electrons to achieve a stable electron configuration. Non - metals form anions because they have 5 - 7 valence electrons and it is easier for them to gain electrons to achieve an octet.

Step10: Electron - dot structure of fluoride ion

Fluorine has 7 valence electrons. It gains one electron to form the fluoride ion ($F^-$). In the electron - dot structure, the symbol F is surrounded by eight dots, with one dot (in a different color to represent the gained electron) being the extra electron.

Step11: Ionic bond

An ionic bond is a type of chemical bond that results from the electrostatic attraction between oppositely charged ions (cations and anions).

Step12: Elements forming ionic compounds

Ionic compounds are formed between metals and non - metals. The metal loses electrons to form a cation, and the non - metal gains those electrons to form an anion, and the electrostatic forces between them hold the compound together.

Step13: Electron - dot structure of sodium chloride

Sodium (Na) has 1 valence electron and chlorine (Cl) has 7 valence electrons. Sodium loses its valence electron to form $Na^+$ and chlorine gains that electron to form $Cl^-$. In the electron - dot structure, the symbol Na with no valence electrons (since it has lost its outer electron) and the symbol Cl with eight valence electrons (including the one it gained) are shown. The electrostatic attraction between $Na^+$ and $Cl^-$ forms the ionic compound sodium chloride.

Answer:

• Reaction of explosive metal with poisonous gas: Varies by specific substances.
• Reaction of pure potassium with water: $2K(s)+2H_2O(l)

ightarrow 2KOH(aq) + H_2(g)$, highly exothermic with possible hydrogen ignition.

• Reaction of potassium chloride with water: $KCl(s)

ightarrow K^+(aq)+Cl^-(aq)$ (dissociation).

• Cause of potassium chloride - water reaction: Polar nature of water.
• Octet Rule: Atoms seek full outer shell of 8 (or 2 for H, He) electrons.
• Stability of elements/compounds fulfilling Octet Rule: Full outer shell gives lower - energy, more stable state.
• Electron - dot structure of argon: 8 dots around Ar, dots represent valence electrons.
• Determination of ion type: Depends on number of valence electrons.
• Elements forming cations and anions: Metals form cations, non - metals form anions.
• Electron - dot structure of fluoride ion: F with 8 dots, one extra dot in a different color.
• Ionic bond: Electrostatic attraction between oppositely charged ions.
• Elements forming ionic compounds: Metals and non - metals.
• Electron - dot structure of sodium chloride: Na with no valence electrons, Cl with 8 valence electrons, held together by electrostatic forces.