Atomic Structure and Ionization Quiz

Atomic Structure

• 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

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

Charge

• 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.

Polarity and Electric Force Fields

• 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

• 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

• 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).

Factors affecting current flow through body tissues

• 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.