Chemistry Flashcards
What is the structure of an ionic substance ?
Metal and Non-Metal lattice structure
Why do ionic substances have a high melting point ?
Lots of energy to break bonds
breaking bonds spreads the molecules out to become liquid
When can an ionic substance conduct electricity ?
When there are delocalised e-
e- conduct the charge
Has to be molten / submerged
What is a covalent bond ?
2 non metals sharing outer electrons
What happens when a covalent bond forms ?
- 2 non metals share electrons to fill their outer shells
What is a molecule ?
2 or more atoms bonded together
What happens when a simple compound is melted ?
Forces between the molecules are broken
Covalent Bonds stay together
Is the melting and boiling point of simple compounds low or high ?
Low
What are properties of metals ?
High melting / Boiling point
Conductor os heat / electricity
Ductile
What is a metallic bond ?
Attraction between a positive ion and delocalised electron
Why do metals have a high boiling point ?
Strong attraction between charged ions and electron
Lots of energy needed to break strong bonds
Why are metals ductile ?
Lattice structure has strong attraction between metal ions and electrons
How do metals conduct electricity ?
Delocalised electrons free to move
can carry electrical charge (flow of electrons) through the metal
What is electronegativity ?
Power of an atom to attract the 2 electrons in a covalent bond
When is a molecule polar ?
When it’s polar bonds are asymmetrical
What are London forces ?
Intermolecular force in every molecule
electrons constantly moving
Temporary dipole
Caused by attraction between partial charges
What are hydrogen intermolecular forces ?
Permanent dipoles that occur between
Oo, N or F and H
