Have an account?
Covalent bonds are formed between...
two or more metal atoms
two or more non-metal atoms
a metal and a non-metal atom
Covalent bonds are formed when electrons are transferred between atoms.
Atoms can only share electrons in the _____ shell.
Fluorine is a diatomic molecule. Fluorine is in Group 7. How many electrons are shared in this covalent bond?
Oxygen is a diatomic molecule. Oxygen is in Group 6. How many electrons are shared in this covalent bond?
The structure of ammonia is shown in the diagram. What is the formula for ammonia?
What are the disadvantages of using displayed formulae, like the one shown?
The 3D structure of the molecule is not shown.
They can show how atoms are bonded in large molecules.
They do not show which atom each electron comes from.
They can be used to find the structural formula of the molecule.
Select the properties of simple covalent substances.
Low melting and boiling points.
High melting and boiling points.
Do not conduct electricity.
Good conductors of electricity.
Why do simple covalent substances not conduct electricity?
They have low melting points.
They have low boiling points.
There are no delocalised electrons or free ions to carry the charge.
The molecules are too large.
Covalent structures have low melting and boiling points because it does not take much energy to break the _____ intermolecular forces.