Anatomy and Philosophy

Unit 2 Lecture Study Guide

1) What are the parts of an atom? Where are the subatomic particles found?

Parts:

1. the central nucleus, contains heavy particles

2. the electron cloud, contains very light, moving particles

Subatomic Particles:

1. Protons- positive charge, about one unit of mass, in the central nucleus

2. Neutrons: no electrical charge( neutral), about one unit of mass, in the central nucleus

3. Electrons: negative charge: very small mass, spin rapidly in a cloud around the central nucleus

2) How does the Atomic Mass # differ from the Atomic #?

Elements are defined by their atomic number, which is the number of protons in the nucleus. The Atomic mass number is determined by adding together the number of protons and neutrons in the nucleus.

3) What is an isotope? Give an example (show how it is an isotope).

Isotopes are atoms of the same element that have different mass numbers due to different numbers of neutrons. Carbon-14 is a radioactive isotope of carbon. It has a half-life of about 5,730 years. The short half-life of carbon-14 means it can’t be used to date extremely old fossils. Levels of carbon-14 become difficult to measure and compare after about 50,000 years

4) Compare and contrast the 3 basic types of chemical bonds and give an example of each.

Chemical Bonds:

1. Ionic Bonds: form between atoms with opposite electrical charges (ions).

i. An atoms that loses electrons and has a net positive charge, called a cation

ii. An atom that gains electrons and a net negative charger, called an anion

iii. Ions in solution can conduct electivity, called electrolytes

iv. Example: table salt, sodium chloride (NaCl)

2. Covalent Bonds: occur when atoms share, rather than gain or lose electrons, forming molecules

i. Each atom contributes the same number of electrons to the bond, called electron pairs...