BIO 143 Lecture Notes - Lecture 2: Hydrophile, Surface Tension, Heat Capacity

45 views4 pages
Chapter 2: Atoms, Molecules, and Life
1. What are atoms?
2. How do atoms interact to form molecules?
A. Chemical bonds
B. Ionic bonds
C.Covalent bonds
D.Hydrogen bonds
3. Why is water so important in life?
A. Water molecules attract one another
B. Water interacts with other molecules
C.Water based solutions can be acidic, basic, or neutral
D.Water moderates the effects of temperature changes
E. Water forms the unusual solid: ice
1. What are atoms?
• Atoms are the fundamental structural units of elements (what is an example of an
element?)
• Atoms are composed of a nucleus with electrons orbiting around it
• The number of protons in the nucleus if called the atomic number, which is the
defining characteristic of each element
• The atomic mass is the total mass of protons, neutrons and electrons
• Atoms of the same element often have different numbers of neutrons referred to as
isotopes of each other
-most isotopes are stables, but some are radioactive: they spontaneously break apart, forming
different atoms and releasing energy in the process
• Radioactive isotopes have become useful tools for studying biological processes:
-medical uses: positron emission tomography devices used in brain scans; X-rays
-smoke detectors
-food irradiation
-archeological dating
• Isotopes of Carbon: Radioactive decay
-a neutron is converted to a proton and also to a low energy electron, which is then emitted
from the atom
Archeological dating: Carbon Dating
• Cosmic ray protons blast nuclei in the upper atmosphere, producing neutrons which
result in bombardment of nitrogen (major element in the atmosphere)
• Electron shells
-a region an atom in which electrons orbit
-the first shell, or energy level, holds two electrons
-the second shell holds up to eight
find more resources at oneclass.com
find more resources at oneclass.com
Unlock document

This preview shows page 1 of the document.
Unlock all 4 pages and 3 million more documents.

Already have an account? Log in

Document Summary

Chapter 2: atoms, molecules, and life: what are atoms, how do atoms interact to form molecules, chemical bonds, ionic bonds. D. hydrogen bonds: why is water so important in life, water molecules attract one another, water interacts with other molecules. C. water based solutions can be acidic, basic, or neutral. Most isotopes are stables, but some are radioactive: they spontaneously break apart, forming different atoms and releasing energy in the process: radioactive isotopes have become useful tools for studying biological processes: Medical uses: positron emission tomography devices used in brain scans; x-rays. A neutron is converted to a proton and also to a low energy electron, which is then emitted from the atom. Archeological dating: carbon dating: cosmic ray protons blast nuclei in the upper atmosphere, producing neutrons which result in bombardment of nitrogen (major element in the atmosphere, electron shells. A region an atom in which electrons orbit. The first shell, or energy level, holds two electrons.

Get access

Grade+20% off
$8 USD/m$10 USD/m
Billed $96 USD annually
Grade+
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
40 Verified Answers
Class+
$8 USD/m
Billed $96 USD annually
Class+
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
30 Verified Answers

Related textbook solutions

Related Documents

Related Questions