Topic 2 - Chemical Bonds Flashcards
When does Ionic bonding occur?
When a metal and non-metal react
What occurs in ionic bonding?
The metal loses electrons to form a positive ion whilst the non-metal takes these electrons to form a negative ion.
What are electrostatic forces?
Oppositely charged ions which attract to one another.
How is sodium oxide formed?
Two sodium atoms give up their outer electron, becoming two positively charged sodium ions whilst the oxygen takes this and becomes a O2-(Two negatives)
What is the structure of an Ionic compound?
A giant ionic lattice.
Name 2 properties of ionic compounds
High melting/boiling points, can’t conduct electricity when solid but can when they melt as ions are free, they can dissolve in water.
Why do ionic compounds have high melting/boiling points?
They have many bonds between the ions so it takes a lot of energy to overcome.
When does Covalent bonding occur?
When non-metals bond together.
What occurs in covalent bonding?
The elements share electrons with one another
Why aren’t dot and cross diagrams so useful for covalent bonds?
They don’t show the relative sizes or arrangements of the atoms.
What occurs in metallic bonding?
The electrons in the outer shell are delocalised and a strong electrostatic force is made between these and the atoms.
Why are alloys harder than pure metals?
They are a mixture of two or more metals and are mixed with pure metals. This means that the new atoms distort the layers of metal atoms making it difficult for them to slide over. This makes it harder.
