Covalent Bonding Flashcards
What are the covalent bonds?
It is when two or more non-metal atoms bond together, they share pairs of electrons to make covalent bonds.
What happens when they share the pairs of electrons?
The positively charged nuclei of the bonded atoms are attracted to the shared pair of electrons by electrostatic forces, making covalent bonds very strong.
In which shell the atoms share electrons?
The atoms only share electrons in their outer shells (highest energy levels).
What is provided when the outer shells of atoms share electrons?
It provides to each single covalent bond one extra shared electron for each atom.
What gives an atom the electronic structure of a noble gas?
Each atom involved generally makes enough covalent bonds to fill up its outer shell. Having a full outer shell gives them the electronic structure of a noble gas, which is very noble.
Which compounds and elements the covalent bonding happens in?
Covalent bonding happens in compounds of non-metals (e.g. H₂O) and in non-metals elements (e.g. Cl₂).
What are the different ways of drawing covalent bonds?
The different ways are the use of dot and cross diagrams to show the bonding in covalent compounds.
What the electrons drawn in the overlap between the outer orbitals of two atoms represent?
That the electrons drawn in the overlap between the outer orbitals of two atoms are shared between those atoms.
What dot and cross are useful for?
They are useful for showing which atoms the electrons in a covalent bond come from.
What is the problem of dot and cross?
That they don’t show the relative sizes of the atoms, or how the atoms are arranged in space.
What the displayed formula of ammonia (NH₃) shows?
Shows that the covalent bonds are single lines between atoms.
The displayed formula of ammonia (NH₃) is it a good or bad way to show how atoms are connected in large molecules?
It is a great way of showing how atoms are connected in large molecules. However, they don’t show the 3D structure of the molecule, or which atoms the electrons in the covalent bond come from.
What the 3D model of ammonia shows and what it doesn’t show?
Show the atoms, the covalent bonds and their arrangement in space next to each other. But 3D models can quickly get confusing for large molecules where there are lots of atoms to include. They don’t show where the electrons in the bonds have come from, either.
What can you find in a simple molecular compound?
You can find the molecular formula of a simple molecular compound from any of these diagram by counting up how many atoms of each element there are.
