a) Electric charge

• define electric current

• the rate of the flow of electric charge

• → the coulombs of charge that pass a specific point in a circuit per second

• state the formula for electric current

• I = ∆Q/∆t

• electric current (A) = charge transferred past a point in the circuit (C) / time (s)

• explain the concept of elementary charge

• one coulomb → contains many electrons/protons

• elementary charge of each electron/proton in one coulomb = ±1.6×10^-19C

• describe how charge is quantised

• charge of any charged object → multiple of elementary charge

• so charge is quantised

• explain the concept of relative charge

• relative charge → measured against elementary charge

• ±1e = ±1.6×10^-19C

• state the formula for the net charge of an object

• Q = ±ne

• net charge of an object (C) = number of electrons lost or gained × elementary charge