Mendeleev · science lesson
Why molecular shape changes properties
Geometry controls how bonds are oriented in space. It influences polarity, reactivity and intermolecular interactions.
Start with the idea
Geometry controls how bonds are oriented in space. It influences polarity, reactivity and intermolecular interactions.
A concrete example
CO₂ is linear and overall nonpolar, while H₂O is bent and polar.
Mendeleev
Mendeleev’s tip
Do not start with a formula. Identify what changes, what stays constant and which quantity you are trying to explain or calculate.
Go one step deeper
CH₄ is tetrahedral, NH₃ pyramidal and H₂O bent: lone pairs alter bond angles and therefore observed geometry.
Common trap
A trend or model is not an exceptionless law. Always check the quantity’s definition and the conditions being compared.
Check your understanding
Can you explain the phenomenon in your own words before looking at an equation?