C4.3/4 - Ionic Bonding/Compounds Flashcards
Hydrogen atoms and metal atoms usually form (I)_________ charged ions, and non-metal atoms usually form (II) ____________ charged ions.
(I) positively
(II) negatively
An ion is easy to spot. They have a ____ or _____ sign at the top right to show if it is positively or negatively charged.
+, -
If Na loses one electron, what will it become?
Na-
What is ionic bonding?
When a metal reacts with a non-metal, electrons are transferred from the metal atoms to the non-metal atoms. The positive metal ions and the negative non-metal ions attract one another, forming ionic bonds.
In a dot and cross diagram, the electrons in the metal are shown as (I) _____ and the electrons in the non-metal are shown as (II) ________.
(I) dots
(II) crosses
What is an ionic compound?
Ionic bonding is the complete transfer of electrons between atoms. It is a type of chemical bond that generates two oppositely charged ions. In ionic bonds, the metal loses electrons to become a positively charged cation, whereas the nonmetal accepts those electrons to become a negatively charged anion. This creates an ionic compound.
What is an ion?
An ion is an electrically charged atom or group of atoms. Electrons are negatively charged:
- If an atom lies one or more electrons, it becomes a positively charged ion.
- If an atom gains one or more electrons, it becomes a negatively charged ion.
Magnesium oxide is an ______ ____________.
Ionic Compound
What is giant ionic lattice?
Giant ionic lattice is the arrangement of atoms in an ionic compound. They are arranged in a regular way. The structure is repeated many times which is why it is called ‘Giant’. The positive ions are attracted to the negative ions, forming ionic bonds.
Why does magnesium oxide and sodium chloride have high melting points and how can it conduct electricity?
Ionic compounds are strong chemical bonds. A lot of energy is needed to break them. This is why sodium chloride and magnesium oxide have high melting points. For an ionic compound to conduct electricity, it’s ions must be free to move from place to place. This can happen in molten liquid or solution, but not in a solid.
How can you work out the formulae of an ionic compound?
You need to know the formulae of ions to work out the chemical formulae of an ionic compound. The number of positive charges has to be aural to the number of negative charges.
E.g sodium chloride contains NA+ and Cl- ions. So the formulae would be NaCl as these both carry one charge.
What would you do to work out the formulae of an ionic compound if the number of charges were uneven?
The number of ions in the formulae must be adjusted. E.g sodium oxide contains Na+ and O2- ions. Two Na+ ions are needed to balance the two charges on the O2- ion, so the formulae would be Na2O.
