BIO 201 (Anatomy) - Exam 1 questions and answers Graded A+ Matter Takes up space and has weight Planetary Model (of atomic structure) Electrons are shown with a fixed orbit on rings at a precise distance from the nucleus. THINK: planet and sun model

BIO 201 (Anatomy) - Exam 1 questions and
answers Graded A+
Matter
Takes up space and has weight
Planetary Model (of atomic structure)
Electrons are shown with a fixed orbit on rings at a precise distance from the
nucleus. THINK: planet and sun model
Atomic Structure
Made up of neutrons, electrons, and protons
Electron Cloud Model
Electrons are floating around in different locations around the nucleus
Protons have a ___ charge
Positive (+)
Neutron have a ___ charge
Neutral - no charge
Electron have a ____ charge
Negative (-)
Nucleus
- The center of the atom
- Made up of protons/neutrons (create atomic mass)
Orbiting the Nucleus
- The electron cloud
- Can add or remove electrons to make ions
- The atom is electrically neutral
Ion

, a charged atom (positive or negative)
Atomic Weight
# protons + # neutrons
- AW is the average mass of ALL isotopes of that element
Atomic Number
# protons (also has same number of electrons)
Atomic Mass
# protons + # neutrons
- AM is the mass of a specific isotope (measured in amu)
Isotopes
Different forms of the same element (different # of neutrons in each isotope)
- same atomic #, different atomic weight
Radioactive Isotope
An isotope that contains more than the usual # of neutrons and becomes
unstable, emitting energy (also called a heavy isotope)

i.e. a radioactive hydrogen isotope is tritium (1 proton, 2 neutrons)
Common Hydrogen Isotopes
1. Protium (1 proton, 0 neutrons)
2. Deuterium (1 proton, 1 neutron)
3. Tritium (1 proton, 2 neutrons) (radioactive)
Cation
Positively charged ion (+)
Formed from losing electrons
Anion
Negatively charged ion (-)
Formed from gaining electrons