Glossary
Coulombs (C)
The SI unit for measuring electric charge, representing a large quantity of charge. One Coulomb is approximately 6.24 x 10^18 elementary charges.
Example:
A lightning bolt can transfer several coulombs (C) of charge between the cloud and the ground in a fraction of a second.
Electric Charge
A fundamental property of matter that causes it to experience a force when placed in an electromagnetic field. It exists in two forms: positive and negative.
Example:
When you rub a balloon on your hair, you transfer electric charge, causing the balloon to stick to a wall.
Electron
A subatomic particle that orbits the nucleus of an atom, carrying a single negative elementary charge (-1e).
Example:
In a conductor, free electrons are responsible for the flow of electric current.
Elementary Charges (e)
The smallest indivisible unit of electric charge, equal to the magnitude of the charge of a single proton or electron (1.6 x 10^-19 C).
Example:
The charge on a single electron is -1 elementary charge (e), which is equivalent to -1.6 x 10^-19 C.
Law of Electrostatics
A fundamental principle stating that electric charges of the same sign repel each other, while electric charges of opposite signs attract each other.
Example:
The reason a positively charged balloon sticks to a negatively charged wall is explained by the Law of Electrostatics.
Like Charges
Electric charges that have the same sign (both positive or both negative). They exert a repulsive force on each other.
Example:
If you bring two positively charged glass rods close together, they will push away from each other due to the repulsion between like charges.
Negative Charge
One of the two types of electric charge, typically associated with electrons. Objects with a net negative charge have an excess of electrons.
Example:
A plastic comb rubbed through dry hair gains a net negative charge as it picks up electrons from the hair.
Neutron
A subatomic particle found in the nucleus of an atom that carries no net electric charge, meaning it is electrically neutral.
Example:
The stability of atomic nuclei is influenced by the presence of neutrons, which help to counteract the repulsion between protons.
Opposite Charges
Electric charges that have different signs (one positive and one negative). They exert an attractive force on each other.
Example:
The attraction between a proton and an electron in an atom is a direct result of them being opposite charges.
Positive Charge
One of the two types of electric charge, typically associated with protons. Objects with a net positive charge have a deficit of electrons.
Example:
A glass rod rubbed with silk acquires a net positive charge because electrons are transferred from the rod to the silk.
Proton
A subatomic particle found in the nucleus of an atom, carrying a single positive elementary charge (+1e).
Example:
The atomic number of an element is determined by the number of protons in its nucleus.