Questions: 3. Common static electricity involves charges ranging from nanocoulombs to microcoulombs. (a) How many electrons are needed to form a charge of -4.00 nC (b) How many electrons must be removed from a neutral object to leave a net charge of +0.2500 μC?
Transcript text: 3. Common static electricity involves charges ranging from nanocoulombs to microcoulombs. (a) How many electrons are needed to form a charge of -4.00 nC (b) How many electrons must be removed from a neutral object to leave a net charge of $+0.2500 \mu \mathrm{C}$?
Solution
Solution Steps
Step 1: Determine the charge of a single electron
The charge of a single electron is e=−1.602×10−19 coulombs.
Step 2: Calculate the number of electrons for -4.00 nC
Given charge Q=−4.00 nanocoulombs (nC).
Convert nanocoulombs to coulombs: Q=−4.00×10−9 coulombs.
Use the formula n=eQ to find the number of electrons.
n=−1.602×10−19−4.00×10−9.
Step 3: Perform the calculation
n≈2.50×1010 electrons.
Step 4: Calculate the number of electrons to be removed for +0.2500 μC
Given charge Q=+0.2500 microcoulombs (μC).
Convert microcoulombs to coulombs: Q=0.2500×10−6 coulombs.
Use the formula n=eQ to find the number of electrons.