Topic 1- bonding Flashcards
(19 cards)
What is an ion?
A charged particle that has different number of protons and electrons.
What is a positive ion?
Ha more protons that electrons- Cation.
What is a negative ion?
Has more electrons than protons.- anion
What do ionic compounds have?
Giant ionic structures.
What is ionic lattice?
the regular arrangements of the ions in ionic structures.
What are features of giant ionic structures?
High melting and boiling points, conducts electricity when dissolved
Does NaCl or MgO have a lower melting point?
NaCl- Lower charge in Na+ and Cl-. Higher charge-stronger bond- more energy needed to break.
Why do giant ionic structures have high melting and boiling points?
Due to the strength of bonds between ions.
Why do giant ionic structures conduct electricity when dissolved?
So that the ions are free to move to carry the charge
When do covalent bonds form?
When the atoms share electrons to get a full outer shell.
What are simple molecular structures?
They consist of a few atoms held together by covalent bonds.
e.g. hydrogen, carbon and water.
What are properties of simple molecular structures?
Low metal and boiling points, do not conduct electricity.
Why do simple molecular structures have low mp and bp?
Due to the weak intermolecular forces between the molecules.
Why can simple molecular structures not conduct electricity?
No free electrons to carry the current.
What is metallic bonding?
When metal atoms bond together. They have giant structures of regularly arranged ions.
What are the electrons doing in metallic bonding?
The electrons from the outer shells of the atoms are delocalised - free to move through the whole structure.
