Atomic Structure and Ionization Quiz

Study Notes

The atom, the smallest unit of matter, consists of a nucleus and electrons.
The nucleus contains protons (positive charge) and neutrons (no charge).
Electrons orbit the nucleus and carry a negative charge.
Atoms with equal protons and electrons are electrically neutral.
Ions occur when an atom gains or loses electrons, resulting in a net positive or negative charge.
The electromagnetic force attracts electrons to the nucleus, while the nuclear force binds protons and neutrons together.

Ionization is the process of an atom or molecule gaining or losing an electron, forming an ion.

Charge is the fundamental aspect of electromagnetic force enabling cell communication.
It's measured in coulombs (C) or microcoulombs (μC).
It represents the net gain or loss of electrons in an atom.
Charge arises from external forces like friction, heat, chemical, or electrical sources.
Key properties of charge:
- Two types: positive and negative.
- Like charges repel, opposites attract.
- Charge is conserved (neither created nor destroyed).
- Charge can be transferred between objects.

In a circuit, one electrode is positive (anode) and the other negative (cathode).
The cathode is the negative pole, while the anode is the positive pole.

Voltage represents the potential energy caused by the attraction/repulsion of an electric field.
Higher force equals higher potential energy.
Measured in volts (V) or millivolts (mV).
Voltage is visualized by the interaction of magnets or charged bodies approaching each other.
Also known as electromotive force, it represents the driving force for electron movement.
In tissues, ions like sodium (Na+), potassium (K+), and chloride (Cl-) are the charged particles moving due to voltage.

Current refers to the movement of ions or electrons in a conductor due to voltage.
Current flow is directly proportional to voltage.
It represents the quantity of ions/electrons flowing at a given time.
Measured in amperes (A) or milliamperes (mA).

Material properties: Materials with more free electrons have less resistance and better current flow (e.g., blood and nerves vs. skin and bone).
Cross-sectional area: Larger area allows greater current flow.