Lecture Notes Review: Drop Units, Chemistry & Matter, Atomic Theory, and Radioactivity

A set of concise Q&A flashcards covering drip units, measurement concepts, matter vs. energy, basic atomic theory, periodic trends, and introductory radioactivity and clinical radiophysics.

What determines the drip rate for IV medications in a bag?

The drop factor (gtt/mL) and the tubing diameter; different tubing yields different drop factors.

What is the difference between accuracy and precision?

Accuracy is how close measurements are to the true value; precision is how close measurements are to each other.

What is Dimension Analysis used for in measurements?

A tool that uses units to solve problems; multiply/divide/cancel units; always include units and ensure they flow logically.

How is matter defined in the notes?

Matter occupies space (has volume); forms of energy are not matter.

What distinguishes physical properties/changes from chemical properties/changes?

Physical properties describe matter without changing composition; physical changes do not alter chemical structure; chemical properties describe how substances react; chemical changes alter composition.

Name some physical properties listed.

Volume, mass, size, weight, length.

What is a substance?

A sample of matter with the same physical and chemical properties throughout (pure).

Define an element.

A substance that cannot be broken down into simpler substances; listed on the periodic table.

Define a compound.

Pure substance made of two or more elements in fixed proportions; properties differ from constituent elements; cannot be separated by physical means.

What are mixtures and their types?

Two or more substances; can be homogeneous (uniform) or heterogeneous (non-uniform); separable by physical means.

What are the basic properties of solids vs. liquids?

Solids have fixed volume and shape; liquids have fixed volume but take the container's shape and flow.

Differentiate metals, nonmetals, and metalloids.

Metals: shiny, high melting points, ductile/malleable, good conductors. Nonmetals: dull, brittle, poor conductors. Metalloids: intermediate properties, semiconductors.

Where are metals generally located on the periodic table?

Toward the bottom left.

Who was Dmitri Mendeleev and what did he contribute?

Formulated an early periodic arrangement of elements based on chemical properties; laid groundwork for the periodic table.

What are periods and groups in the periodic table?

Periods are horizontal rows; groups (families) are vertical columns with similar properties.

What is an atom?

The smallest unit of an element that retains the identity of that element.

What is a molecule?

Two or more atoms bonded together; can be same or different elements.

Where are protons, neutrons, and electrons located in an atom?

Protons and neutrons in the nucleus; electrons orbit outside the nucleus.

What is the atomic number Z?

Number of protons; determines the element's identity; equals the number of electrons in a neutral atom.

What is the mass number A?

Protons plus neutrons; determines the isotope's mass.

What are isotopes?

Atoms of the same element (same Z) with different numbers of neutrons and thus different masses.

What is atomic mass?

The average mass of naturally occurring isotopes of an element, weighted by abundance.

What is a valence electron?

Electrons in the outermost shell; drive chemical properties; the group number often indicates the number of valence electrons.

What is the octet rule?

Most atoms prefer to have eight valence electrons for stability.

What do energy shells and periods indicate?

Electrons occupy shells; the period corresponds to the number of shells; inner shells are lower in energy.

What is electronegativity?

An atom's ability to attract electrons; generally increases across a period and decreases down a group.

What is ionization energy?

Energy required to remove a valence electron; rises across a period and falls down a group.

Define radioactivity.

Emission of particles by unstable nuclei to form a more stable nucleus.

Name the forms of radioactivity.

Alpha particles, beta particles, gamma radiation, positron emission/electron capture, and nuclear fission.

Describe alpha decay.

Emission of an alpha particle (2 protons, 2 neutrons); nucleus loses mass and Z; +2 charge with the emitted particle.

Describe beta decay.

Emission of an electron (beta particle) from the nucleus; -1 charge with negligible mass; nucleus converts neutrons to protons or vice versa to balance.

Describe gamma decay.

Emission of electromagnetic radiation (photons) with no mass or charge; often accompanies other decays; nucleus ends in a lower energy state.

What is electromagnetic radiation and how are energy, frequency, and wavelength related?

Light energy travels as photons; E = h f; f = c/λ; higher frequency means higher energy; shorter wavelengths connect to higher energy.

What is ionizing radiation and why is it biologically significant?

Radiation that ionizes atoms by removing electrons; can damage biomolecules; more harmful to rapidly dividing cells.

What are radioactive tracers and give examples?

Radioisotopes that behave like stable isotopes but emit detectable radiation; examples: I-131 (thyroid), Na-24, Tl-201, Tc-99m.

What is Positron Emission Tomography (PET)?

Uses positron-emitting tracers; annihilation with electrons produces gamma rays detected to image organ function.

What are radiopharmaceutical applications in medicine?

Surgery planning/execution, diagnostic imaging, and therapeutic use; e.g., iodine-based tracers for thyroid.

What is radiotherapy and its clinical use?

Use of high-energy ionizing radiation to kill rapidly dividing cells; external beam or brachytherapy.

How do smoke detectors with Americium-241 work?

Am-241 alpha particles ionize air; resulting current is disrupted by smoke, triggering alarm.

What is half-life?

The time required for half of the radioactive nuclei in a sample to decay; isotope-specific and used to predict activity duration.

What is nuclear fission?

Splitting of a heavy nucleus into smaller nuclei, releasing energy and often creating multiple daughter products.

Why is half-life important for clinical isotopes?

Determines scheduling, safety, and how long an isotope remains active in a patient or product.