Simple Molecular Substances Flashcards
What are simple molecular substances made up from
Small molecules joined together by covalent bonds
How is hydrogen a simple molecular substance
H2
Just have one electron, they need only one more to complete the first shell
Form a single covalent bond
How is chlorine an example of simple molecular substances
Cl2
Each chlorine atom needs one more electron to complete the outer shell
So two chlorine can
How is oxygen an example of simple molecular substances
o2
Needs 2 more electrons to complete its outer shell
Two oxygen atoms share two pairs of electrons with eachother, making a double covalent bond
How is nitrogen an example of simple
Molecular substances
N2
Needs 3 more electrons so two nitrogen atoms share three pairs of electrons to fill their outer shell
This is a triple bond
How is methane an example of simple molecular substances
Ch4
Carbon has 4 outer electrons which is half a full shell
It can form 4 covalent bonds with hydrogen to fill up
How is water an example of a simple molecular substances
H2O
In water molecules, the oxygen shares a pair of electrons with two hydrogen atoms to form two single covalent bonds
How is hydrogen chloride an example of simple molecular substances
Both atoms only need one more electron to complete their outer shell
What are 5 properties of simple molecular substances
- The atoms within the molecules are held together by very strong covalent bonds, the forces of attraction between these molecules are very weak
- To melt or boil a simple molecular compound, you only need to break these intermolecular forces and not the covalent bonds, melting and boiling points are low
- Most are gases or liquids at room temperature
- As they get bigger, the intermolecular forces increase, so more energy is need to break them, the melting and boiling points increase
- Molecular compounds don’t conduct electricity, because they’re not charged, so no free electrons to move
