Unit 2: 1 - Chemical Bonding Flashcards
What bond is created between 2 non-metallic elements?
Covalent. This is where they share electrons.
What is special about noble gases?
They have stable electronic structures.
What bond is created by a metal and a non-metal?
Ionic. The metal atom loses electrons to become positive. The non-metal atom gains those electrons to become negative.
What relationship does the groups of the periodic table have with the elements in the group?
The group number is the amount of electrons in the outer shell.
How many electrons are in the shells (first, second, third)?
2,8,8
What is special about the size of the structures made by ionic bonding? How does it occur?
Ionic structures are giant. This is why we get big salt crystals. Oppositely charged ions hold each other neatly in place with strong electrostatic forces. This is called a cubic lattice is sodium chloride.
How do we show ionic boning in diagrams?
A dot and cross diagram. One ion has dots, the other crosses, and the non-metallic ion has x number of crosses from the metallic ion.
How do we tell what ionic charge a transition metal will have?
It is the Roman Numeral in the name, e.g. Copper (II) sulphate has a Cu2+ ion.
Can ions consist of more than one element?
Yes. For example hydroxide ions are OH-. In a compound these hydroxide ions need to be in brackets.
What is a molecule?
Molecule are covalently bonded substances
How do we draw covalent bonds?
We use lines (e.g. H—-O—-H) or show electrons.
How many covalent bonds can a certain atom make?
It all depends on the group. Group 7 can only form 1 as they need a full outer shell. Group 5 forms 3 and so on.
The formula is Number of bonds = Outer shell size - Group number.
What is metallic bonding?
When metal atoms pack together, many electrons become delocalised. This makes a lattice of positive ions, and the negative delocalised electrons strongly attract the ions to each other.
