Melting Point Flashcards
What does metallic bonding consist of?
A lattice of positively charged ions surrounded by a “sea” of delocalised electrons
What holds the metallic lattice together?
Very strong electrostatic forces of attraction between the positive metal ions and negative electrons
Why is there a greater attractive force if there is a larger positive charge on the metal ion?
More electrons are released into the “sea”
Why do larger ions produce a weaker attraction?
They have a greater atomic radius which decreases the charge density
How do delocalised electrons In a metallic lattice prevent fragmentation?
They can move around the lattice so like charges don’t come into contact and repel.
What are 4 properties of metals?
1) good conductors
2) malleable
3) High melting points
4) solid at room temperature
Why do metals have high melting points?
There is very strong electrostatic forces of attraction between the positive ions and delocalised electrons which require lots of energy to overcome.
What is the only metal that is liquid at room temperature?
Mercury
What is a giant covalent lattice?
A network of atoms bonded by many strong covalent bonds
Why do giant covalent structures have high melting points?
Each atom within the lattice has multiple covalent bonds which are very strong
Generally put, why do the melting points of period 2 elements peak towards the middle of the period?
Different bond strength and structures.
Why do the melting points increase from group 1 to 2?
Greater positive charge of the ions and so more electrons released so there are greater attractive forces.
What two groups have the highest boiling points ?
Group 14 (highest)
Group 13
What groups have similar melting points due to being simple covalent molecules?
Group 15, 16, 17 and 18.
Why do simple covalent molecules have low melting points?
They have weak London forces between molecules.
