Exam 1 Flashcards
(49 cards)
What is science and how do scientists obtain knowledge?
From the Latin verb “to know”
Via the scientific method
What is the scientific method?
Use of deductive reasoning.
Observe
Question
Hypothesis
Prediction
Experiment
Conclusion
What are the differences between deductive and inductive reasoning?
Deductive leads one to infer something specific from a general premise
Inductive leads one to infer general principles from specific examples
What is a scientific theory?
Widely accepted explanation that is broad in scope and supported by large body of evidence
What is the role of peer review in science?
To double check for problems or errors in reports by experts with equal or greater knowledge
What is a sampling error and how can its impact be reduced in an experiment?
Non representative samples skew results. Minimized by using large samples
Characteristics of a living organism
- made of cells from macromolecules
- growth, development, reproduction
- heritable information in the form of DNA
- Sensitivity to stimuli
- homeostasis
- use of energy
How many elements occur naturally on earth?
92
Four most common elements in living things
Oxygen
Hydrogen
Carbon
Nitrogen
What is an atom and what are its major sub-atomic particles?
Smallest particles that retain properties of an element
-protons
-electrons
-neutrons
What does an element’s atomic number tell us?
Number of protons
What is an atoms mass number?
Number of protons + number of neutrons
What is an isotope?
Atoms of an element with different numbers of neutrons (different mass numbers)
What are radioisotopes and what are some of their uses?
Have an unstable nucleus that emits energy and particles. Radioactive decay transforms radioisotope into a different element.
Uses:
- drive older pacemakers
- PET Scan
- Radiation therapy
- tracers
How many electrons are in an uncharged (non-ionic) atom?
Equal to number of protons
Where are electrons found around an atom?
Orbitals
How many electrons can each orbital hold?
First shell holds 2, second holds 8
In what order are electron shells filled?
Closest to nucleus then out
How do vacancies in the outer electron shell effect atoms?
Male atoms likely to react with other atoms
Name and describe the types of chemical bonds that are important in biology
- ionic bonds: atoms give or take electrons
- covalent bonds: share electrons
- hydrogen bonds: 2 separate molecules attracted
What are ions and how are they formed?
Molecules with pos or neg charge
Form through ionic bonding: when (-) ion and (+) ion are attracted to each other
What is a covalent bond?
Atoms share a pair or pairs of electrons to fill outermost shell
How are polar and non-polar covalent bonds different?
Non polar: nuclei of atoms have same number of protons
Polar covalent bonds: number of protons in nuclei is not equal
How do covalent and ionic bonds differ?
Ionic bonds gain or lose electrons. Covalent bonds share electrons
