Why do atoms form chemical bonds?
To achieve a more stable electron arrangement, usually a full valence shell (like noble gases).
hat is a chemical bond?
chemical bond is a lasting, strong attraction between atoms that allows atoms to reach a lower energy state and form molecules, crystals and other compounds
How can atoms bond?
Losing electrons → ionic
Gaining electrons → ionic
Sharing electrons → covalent
What is valency?
The combining power of an atom — how many electrons it requires to achieve a stable electron configuration
What ions do metals form?
Cations (they lose electrons)
What ions do non-metals form?
Anions (they gain electrons)
Why do atoms form ions?
To achieve a full valence shell → stability
What is an ionic bond?
a bond forned by electrostatic attraction between oppositely charged ions
How do ionic bonds form?
Metal loses electrons → cation
Non-metal gains electrons → anion
Opposite charges attract
When do ionic bonds usually form?
: Between a metal and non-metal with a large electronegativity difference
Why are ionic compounds stable?
they form strong, three-dimensional crystal lattices held together by powerful electrostatic attractions between oppositely charged ions
Q: What structure do ionic compounds form?
A: A giant ionic lattice (3D crystal structure)
Q: What holds the lattice together?
A: Strong electrostatic forces between ions
Q: Why are ionic compounds hard?
A: Strong forces between ions make the structure rigid
Q: Why do ionic compounds have high melting/boiling points?
A: A lot of energy is needed to overcome strong ionic bonds
Why are ionic compounds brittle?
When layers shift, like charges align
Strong repulsion → lattice breaks → shattering
Do ionic solids conduct electricity?
No, charged ions are locked into a rigid, fixed crystal lattice
Q: Do molten ionic compounds conduct electricity?
Yes — ions are free to move
Do ionic solutions conduct electricity?
✅ Yes — ions are dissolved and mobile
What is a polyatomic ion?
A group of atoms acting as one charged unit
Examples of polyatomic ions
NH₄⁺ (ammonium)
CO₃²⁻ (carbonate)
SO₄²⁻ (sulfate)
OH⁻ (hydroxide)
NO₃⁻ (nitrate)
: Key rule for naming polyatomic ions
Keep their names unchanged
How are transition metals named?
Use Roman numerals to show charge
Example:
Fe²⁺ → iron(II)
Fe³⁺ → iron(III)
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Week 2.1: The Atom31
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Week 2.0 Development of the models of the atom40
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Week 3.0 Electron shells and configurations28
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Elemental spectroscopy30
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Isotopes32
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Week 5: Periodic Trends25
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More periodic trends but this time it is actually periodic trends37
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Matter and properties32
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Separation Techniques36
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Mettalic bonding21
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Ionic Bonding26
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Naming chemical compunds31
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Common Chemical Reactions35
