COVALENT Bonding Flashcards
When atoms _____ pairs of _______, they form _______ bonds.
When atoms share pairs of electrons, they form covalent bonds.
Covalently bonded substances may consist of _________
Covalently bonded substances may consist of small molecules.
Some covalently bonded substances have very _________molecules such as: _________
Some covalently bonded substances have very large molecules,such as polymers.
Some covalently bonded substances have _______covalent
structures, such as __________and _____________
Some covalently bonded substances have giant covalent
structures, such as diamond and silicon dioxide
Covalent bonds are formed between what type of atom
Covalent bonds are formed between non-metals
Covalent bonds invlolve _______ electrons
Covalent bonds involve sharing electrons
Name type of structures where their atoms are covalently bonded
Structures where their atoms are covalently bonded include:
Simple covalent molecules
Giant covalent structures
Define covalent bond
The attraction between two atoms that share one or more pairs of electrons
Give examples of simple covalent molecules
hydrogen,
chlorine,
oxygen,
nitrogen,
hydrogen chloride,
water,
ammonia
methane
What happens when a covalent molecules melts
When a covalent molecules melts, it is the intermolecular forces that break
What holds the atoms of simple covalent molecules and giant covalent structures together
Strong covalent bonds hold the atoms of the simple covalent molecules and giant covalent structures together.
What happens when simple covalent molecules change state
When simple covalent molecules change state, it is the weak intermolecular forces that break
In terms of the intermolecular forces, describe the structure of a gas of a simple covalent molecule
In a gas, the weak intermolecular forces have completely broken
Draw the dot and cross diagram and stick diagram for hydrogen and state the formula
file:///C:/Users/44748/Documents/dot%20and%20cross,%20stick%20diagram%20diagrams%20of%20simple%20covalent%20molecules.pdf
Draw the dot and cross diagram and stick diagram for ammonia and state the formula
file:///C:/Users/44748/Documents/dot%20and%20cross,%20stick%20diagram%20diagrams%20of%20simple%20covalent%20molecules.pdf
Draw the dot and cross diagram and stick diagram for water and state the formula
file:///C:/Users/44748/Documents/dot%20and%20cross,%20stick%20diagram%20diagrams%20of%20simple%20covalent%20molecules.pdf
Draw the dot and cross diagram and stick diagram for chlorine and state the formula
file:///C:/Users/44748/Documents/dot%20and%20cross,%20stick%20diagram%20diagrams%20of%20simple%20covalent%20molecules.pdf
Draw the dot and cross diagram and stick diagram for oxygen and state the formula
file:///C:/Users/44748/Documents/dot%20and%20cross,%20stick%20diagram%20diagrams%20of%20simple%20covalent%20molecules.pdf
Draw the dot and cross diagram and stick diagram for hydrogen chloride and state the formula
file:///C:/Users/44748/Documents/dot%20and%20cross,%20stick%20diagram%20diagrams%20of%20simple%20covalent%20molecules.pdf
Draw the dot and cross diagram and stick diagram for carbon dioxide and state the formula
file:///C:/Users/44748/Documents/dot%20and%20cross,%20stick%20diagram%20diagrams%20of%20simple%20covalent%20molecules.pdf
Draw the dot and cross diagram and stick diagram for methane and state the formula
file:///C:/Users/44748/Documents/dot%20and%20cross,%20stick%20diagram%20diagrams%20of%20simple%20covalent%20molecules.pdf
In what state are small covalent molecules, usually, at room temperature and why?
Small covalent molecules are usually gases or liquids at room temperature (due to low mp and bp due to weak intermolecular forces)
State the properties of Small covalent molecules
Small covalent molecules low melting points and boiling points.
Small covalent molecules do not conduct electricity
Small covalent molecules are usually liquids or gases at room temperature
Explain why simple covalent molecules do not conduct electricity
Simple covalent molecules do not conduct electricity. This is because the molecules do not have an overall electric charge
(show this to sir + spec.)
Simple covalent molecules do not have any delocalised electrons or ions so it cannot carry a charge through the simple molecular (covalent) structure
Explain why simple covalent molecules have low boiling and melting points
Simple covalent molecules have weak intermolecular forces. The weak intermolecular forces between the molecules do not require a lot of energy to break, therefore simple covalent molecules have low melting and boiling points.
State the simple covalent molecule which is a liquid at room temperature
Water
State the simple covalent molecules which are a gas at room temperature
Ammonia
Oxygen
Nitrogen
Methane
Hydrogen Chloride
Chlorine
Hydrogen
Carbon dioxide
The weak forces between each molecule of a simple covalent molecules are called __________
The weak forces between each molecule of a simple covalent molecules are called intermolecular forces.
The atoms in each molecule are held together by _________
The atoms in each molecule are held together by STRONG covalent bonds
Substances that consist of small molecules are usually _________or _________________
Substances that consist of small molecules are usually gases or liquids
What do small covalent structures have between the molecules
These substances have only weak forces between the molecules (intermolecular forces)
When a simple covalent molecule melts or boils, what is overcome
It is these intermolecular forces that are overcome, not the covalent bonds, when the simple covalent molecule melts or boils.
Why do larger simple covalent molecules have higher melting and boiling points
The intermolecular forces increase with the size of the
simple covalent molecules, so larger molecules have higher melting and boiling points as the intermolecular forces increase and require more energy to break.
Describe the trend with the intermolecular forces and size of simple covalent molecules
The intermolecular forces increase with the size of the molecules
What do larger, simple covalent molecules have that smaller, simple covalent molecules do not have
Larger simple covalent molecules molecules have higher melting and boiling points.
