Video Notes Review: Science, Evolution, Atomic Structure, Bonding, and Taxonomy

A set of Q&A flashcards covering science methodology, classification, evolution, atomic structure, chemical bonding, and taxonomy based on the lecture notes.

What are the steps of the scientific method

Observation → question → hypothesis → experiment → conclusion.

hypothesis.

An explanation for an observed phenomenon (an educated guess or proposed answer).

Define a theory.

A unified explanation for many observations.

law or principle.

An expression of a mathematical or physical relationship.

What characteristics make a scientific statement testable?

It must be falsifiable, based on observations/data, and capable of making testable predictions.

How do theories, laws, and hypotheses differ in breadth and refinement?

Theories are broad; laws and hypotheses are more specific. Theories and laws can be refined over time; hypotheses are accepted or rejected based on evidence.

What are the three domains of life?

Bacteria, Archaea, and Eukarya.

Within Domain Eukarya, what kingdoms are included

Plantae, Fungi, Protists, and Animalia.

basic tenets of evolution by natural selection (Darwin)?

Descent with modification: variation exists, overproduction leads to competition, unequal fitness leads to differential survival, and heritable traits drive population evolution.

What must be true for evolution to work in terms of traits?

Traits must be heritable.

What is the basic unit of life?

The cell.

key characteristics that define living things

Have one or more cells; require energy; metabolize; respond to stimuli; adapt; reproduce.

What did Darwin propose about descent with modification?

Living things become adapted for their environment over time through descent from common ancestors.

What are protons, neutrons, and electrons?

Subatomic particles: protons (positive charge), neutrons (neutral), electrons (negative charge).

What is the atomic number?

The number of protons in the nucleus.

What is the mass number?

The total number of protons and neutrons in the nucleus.

What are isotopes?

Different atomic forms of an element containing different numbers of neutrons.

What is electron configuration?

The arrangement of electrons in energy levels (shells) and orbitals around the nucleus.

What is valence (in chemistry)?

The outermost electron shell and the number of electrons needed to fill it.

ionic bonding

One atom loses electrons (cation) and another gains electrons (anion) to form ions.

What is covalent bonding?

Sharing of electrons between two atoms based on electronegativity.

difference between polar and nonpolar covalent bonds?

Nonpolar covalent bonds share electrons equally; polar covalent bonds share electrons unequally.

hydrogen bonding?

A hydrogen atom bonded to a highly electronegative atom creates a slightly positive pole that can attract a negative pole of another molecule.

What are van der Waals forces?

Weak, transient forces due to momentary charges that can cause attraction or repulsion between molecules.

What are the typical capacities of the first three electron shells?

1st shell: 2 electrons; 2nd shell: 8 electrons; 3rd shell: up to 18 electrons (often fills to 8 in many contexts).

What is an atom?

The smallest unit that retains the properties of an element.

What determines the properties of substances in relation to atoms?

The atom's structure and the arrangement of electrons determine chemical properties and behavior.

What does Descent with Modification mean in evolution?

Over generations, populations accumulate changes as individuals with favorable traits reproduce more successfully.

What is fitness in the context of natural selection?

Reproductive success and the ability to pass advantageous traits to offspring.

What taxonomic ranks are included in domain to species?

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.