Chemical Changes and Structure - Structure and Bonding in the First 20 Elements Flashcards
How does the periodic table display the elements?
In order of increasing atomic number.
What do elements in the same group have in common?
They all have the same number of outer electrons.
What is metallic bonding, what is its melting point and can it conduct electricity?
Positive ions surrounded by delocalised electrons.
High melting point.
Yes, it conducts electricity.
What are covalent molecules?
Small groups of atoms held together by strong covalent bonds inside the molecule and weak London Dispersion Forces between the molecules. The covalent bond is a shared pain of electrons to have a stable arrangement.
What is the formula of Phosphorous, Sulfur and Fullerenes?
P₄, S₈ and C₆₀.
What is the melting point of covalent molecules and why? Why do Phosphorous, Sulfur and Fullerenes have higher melting points?
Covalent molecules have low melting points since only the weak London Dispersion Forces have to be broken. Phosphorous, Sulfur and Fullerenes may have higher melting pints as they have more electrons and stronger London Dispersion Forces.
What are covalent networks and what are their melting point?
They are large, 3D atoms held together by strong covalent bonds. They have very high melting points.
What makes Graphite an effective lubricant?
The hexagonal layers are held together by London Dispersion Forces, allowing the layers to move easily.
What are monatomic elements melting points and why?
They have low melting points as they are held together by weak London Dispersion Forces.
