Quick Review Flashcards - Click to flip and test your knowledge!
Question
What is the term for the force that holds two or more atoms together in a stable molecule?
Answer
Chemical bond
Question
Name the three sub-atomic particles that build up an atom.
Answer
Protons, neutrons, and electrons
Question
What is the mass of a proton in $C-12$ standard units?
Answer
$1 \text{ a.m.u.}$
Question
Which sub-atomic particle has a mass that is considered 'negligible'?
Answer
Electron
Question
Elements are pure substances made up of one kind of atoms that share the same _____.
Answer
Atomic number
Question
How many electrons are typically found in the valence shell of metallic elements?
Answer
$1$, $2$, or $3$ electrons
Question
Metallic elements tend to lose electrons to become positively charged ions called _____.
Answer
Cations
Question
Non-metallic elements tend to gain electrons to become negatively charged ions called _____.
Answer
Anions
Question
What are the two primary means by which atoms combine to form a molecule?
Answer
Transfer of valence electrons and sharing of valence electrons
Question
Why are noble gases such as Helium and Neon considered chemically inert?
Answer
They have stable electronic configurations with complete outermost shells.
Question
Term: Duplet rule
Answer
Definition: The tendency of an atom to achieve two electrons in its outermost shell, similar to Helium.
Question
Term: Octet rule
Answer
Definition: The tendency of an atom to achieve eight electrons in its outermost shell to reach stability.
Question
What type of chemical bond is formed by the transfer of valence electrons from one atom to another?
Answer
Electrovalent (or ionic) bond
Question
What type of chemical bond is formed by the mutual sharing of pairs of electrons between reacting atoms?
Answer
Covalent bond
Question
To facilitate the formation of an ionic compound, what should be the value of the metallic atom's ionisation potential?
Answer
Lower
Question
For the formation of an ionic compound, the non-metallic atom should have a _____ electron affinity.
Answer
Higher
Question
Under what condition regarding electronegativity does electron transfer between atoms take place most easily?
Answer
When there is a large difference in electronegativity between the combining atoms.
Question
The number of electrons donated or accepted by the valence shell of an atom to achieve stability is called _____.
Answer
Electrovalency
Question
In terms of electron transfer, how is 'oxidation' defined?
Answer
A process where an atom or ion loses electrons.
Question
In terms of electron transfer, how is 'reduction' defined?
Answer
A process where an atom or ion gains electrons.
Question
What term describes a reaction where both oxidation and reduction occur simultaneously?
Answer
Redox reaction
Question
What specific force of attraction holds the oppositely charged ions together in an electrovalent compound?
Answer
Electrostatic force of attraction
Question
Which noble gas configuration does a Sodium ion ($Na^{+}$) attain after losing one electron?
Answer
Neon ($2, 8$)
Question
Which noble gas configuration does a Chloride ion ($Cl^{-}$) attain after gaining one electron?
Answer
Argon ($2, 8, 8$)
Question
In the formation of Calcium oxide ($CaO$), how many electrons are transferred from the Calcium atom to the Oxygen atom?
Answer
$2$ electrons
Question
Why must one Magnesium atom combine with two Chlorine atoms to form Magnesium chloride ($MgCl_{2}$)?
Answer
Magnesium donates two electrons, while each Chlorine atom can only accept one.
Question
What is the covalent bond formed by the sharing of one pair of electrons between two atoms called?
Answer
Single covalent bond
Question
Which molecule is a classic example of a triple covalent bond formed by sharing three pairs of electrons?
Answer
Nitrogen ($N_{2}$)
Question
Term: Covalency
Answer
Definition: The number of electron pairs which an atom shares to achieve a stable electronic configuration.
Question
A covalent bond is said to be _____ when the shared pair of electrons is equally distributed between the two atoms.
Answer
Non-polar
Question
What causes a covalent bond to become polar?
Answer
An unequal distribution of shared electrons due to a difference in electronegativity.
Question
In a polar covalent molecule, the atom with higher electronegativity develops a slight _____ charge.
Answer
Negative ($\delta^{-}$)
Question
Identify the four single covalent bonds in a Methane ($CH_{4}$) molecule.
Answer
Each of the four Hydrogen atoms shares one electron pair with the central Carbon atom.
Question
How many lone pairs of electrons are present on the Oxygen atom in a Water ($H_{2}O$) molecule?
Answer
$2$ lone pairs
Question
How many lone pairs of electrons are present on the Nitrogen atom in an Ammonia ($NH_{3}$) molecule?
Answer
$1$ lone pair
Question
Term: Coordinate bond
Answer
Definition: A bond formed by a shared pair of electrons where both electrons come from the same atom.
Question
What is the requirement for an atom to provide the shared pair in a coordinate bond?
Answer
It must have at least one lone pair of electrons.
Question
The Hydronium ion ($H_{3}O^{+}$) is formed when a Water molecule provides a lone pair to a _____.
Answer
Hydrogen ion ($H^{+}$)
Question
Which ion is formed when an Ammonia molecule ($NH_{3}$) forms a coordinate bond with a Hydrogen ion ($H^{+}$)?
Answer
Ammonium ion ($NH_{4}^{+}$)
Question
In what physical state do electrovalent compounds typically exist at room temperature?
Answer
Crystalline hard solids
Question
What are the constituent units of covalent compounds?
Answer
Molecules
Question
Why do electrovalent compounds have high melting and boiling points?
Answer
Strong electrostatic forces between ions require large amounts of energy to break.
Question
Covalent compounds generally have low melting points due to the presence of weak _____ forces between molecules.
Answer
Van der Waal's
Question
Under what conditions do electrovalent compounds conduct electricity?
Answer
In the molten state or in aqueous solution.
Question
Why are electrovalent compounds non-conductors of electricity in the solid state?
Answer
The electrostatic force keeps ions in fixed positions, so there are no free ions to migrate.
Question
Why do polar covalent compounds like $HCl$ conduct electricity when dissolved in water?
Answer
They undergo ionisation in water, creating free ions.
Question
What is the general solubility of electrovalent compounds in organic solvents like benzene?
Answer
Insoluble
Question
Covalent compounds are generally soluble in _____ solvents.
Answer
Organic (non-polar)
Question
Which type of compounds undergo high-speed reactions involving ions?
Answer
Electrovalent (ionic) compounds
Question
Term: Electrolytic dissociation
Answer
Definition: The process of separation of ions already present in an ionic compound upon the passage of electric current.
Question
Term: Ionisation
Answer
Definition: The formation of ions from molecules which are not initially in an ionic state (e.g., in polar covalent compounds).
Question
Identify a compound that contains electrovalent, covalent, and coordinate bonds simultaneously.
Answer
Ammonium chloride ($NH_{4}Cl$)
Question
In the molecule $CCl_{4}$, what is the specific type of covalent bond present?
Answer
Non-polar covalent bond
Question
What is the atomic number of Chlorine, and what is its electronic configuration?
Answer
Atomic number $17$; Configuration $2, 8, 7$.
Question
What is the atomic number of Magnesium, and what is its electronic configuration?
Answer
Atomic number $12$; Configuration $2, 8, 2$.
Question
Why is Hydrogen gas ($H_{2}$) considered a non-polar covalent molecule?
Answer
The shared pair of electrons is shared equally between two identical atoms.
Question
In a coordinate bond, the atom that contributes the electron pair is the donor, and the atom that receives it is the _____.
Answer
Acceptor
Question
Which element has the electronic configuration $2, 4$?
Answer
Carbon
Question
How many electrons does Oxygen ($2, 6$) need to share to attain a stable octet structure?
Answer
$2$ electrons
Question
What is the term for a pair of electrons not shared with any other atom in a molecule?
Answer
Lone pair