💎 • Lesson 2.2 : Elements and Compounds (Chem) Flashcards
This deck will cover atoms, elements, and compounds more in depth. From simple molecules and covalent bonds to giant covalent structures. Going through Ions and Ionic bonds, and even metallic bonding.
What is the formation of positive ions (cations) and negative ions (anions)?
Positive ions (cations) form when atoms lose electrons, while negative ions (anions) form when atoms gain electrons.
What is an ionic bond?
An ionic bond is a strong electrostatic attraction between oppositely charged ions.
How do ionic bonds form between elements from Group I and Group VII (7)?
Group I elements lose an electron to form positive ions, while Group VII elements gain an electron to form negative ions, creating an ionic bond.
How do ionic bonds form between ions of metallic and non-metallic elements?
Metallic elements lose electrons to form positive ions, while non-metallic elements gain electrons to form negative ions, resulting in an ionic bond.
What are the properties of ionic compounds?
Ionic compounds have high melting and boiling points, good electrical conductivity when aqueous or molten but poor when solid. They are generally soluble in water.
Why do ionic compounds have high melting and boiling points?
Ionic compounds have strong electrostatic forces between ions, requiring a lot of energy to break them.
Why do ionic compounds conduct electricity when aqueous or molten but not when solid?
Ionic compounds can only conduct electricity when their ions are free to move, which happens in aqueous or molten states.
What is the giant lattice structure of ionic compounds?
Ionic compounds have a giant lattice structure, a regular arrangement of alternating positive and negative ions, like in sodium chloride.
What is a covalent bond?
A covalent bond forms when two atoms share a pair of electrons, achieving a noble gas electronic configuration.
How do covalent bonds form in simple molecules like H₂, Cl₂, H₂O, CH₄, NH₃, and HCl?
Atoms share electrons to complete their outer shells.
How do covalent bonds form in molecules like CH₃OH, C₂H₄, O₂, CO₂, and N₂?
Atoms share electrons, sometimes forming double or triple bonds.
What are the properties of simple molecular compounds?
Low melting and boiling points and poor electrical conductivity.
Why do simple molecular compounds have low melting and boiling points?
They have weak intermolecular forces that require little energy to break.
Why do simple molecular compounds have poor electrical conductivity?
They have no free-moving electrons or charged particles to carry a current.
What is the structure of diamond?
Diamond has a giant covalent structure where each carbon atom is bonded to four others in a tetrahedral arrangement.
What is the structure of graphite?
Graphite has a giant covalent structure where each carbon atom is bonded to three others in hexagonal layers, with weak forces between layers.
Why is graphite used as a lubricant and electrode?
Lubricant — Weak forces between layers allow them to slide.
Electrode — Delocalized electrons allow it to conduct electricity.
Why is diamond used in cutting tools?
It is extremely hard due to its strong covalent bonds in a rigid tetrahedral structure.
What is metallic bonding?
It is the electrostatic attraction between positive metal ions and a ‘sea’ of delocalized electrons.
Why do metals conduct electricity?
Delocalized electrons move freely and carry charge.
Why are metals malleable?
Layers of metal ions can slide over each other without breaking bonds.
