What is a covalent bond?
A bond formed between oppositely charged ions
A bond formed when two atoms share a pair of electrons
A bond formed by delocalised electrons
How many different types of atom are in an NH3 molecule?
2
3
4
In a dot and cross diagram, what does each dot represent?
A neutron
A proton
An electron
What is the greatest number of covalent bonds that one carbon atom can form?
How many electrons are shared in a double bond?
8
When a substance made of small molecules boils, what does the energy overcome?
Intermolecular forces
Ionic bonds
Covalent bonds
Which statement best explains why substances made of small molecules cannot conduct electricity?
They have no charged particles that are free to move from place to place
They cannot move from place to place
They have no charged particles
What is the formula of methane?
CH5
CH4
NH3
What is a triple bond?
Three pairs of electrons shared between two atoms
Three electrons shared between two atoms
Two electrons shared between three atoms
What is the total number of atoms in an H2O molecule?