Chapter 2 Study Guide
1. Identify the 2 components the compose everything in the universe.
matter and energy
2. Identify the 3 states of matter and the example of each from the lecture slides.
solid- ice cube
liquid- water
gas- water vapor
3. Identify the 6 major elements that compose the majority of our bodies.
1. oxygen - 65%
2. carbon - 15.5%
3. hydrogen - 9.5%
4. nitrogen - 3.0%
5. calcium - 1.5%
6. phosphorus - 1.0%
4. Describe the structure of an atom. Include charges of each subatomic particle.
atom is the smallest particle that exhibits chemical properties of an element.
Subatomic particles :
proton - positive charge
neutron - no charge
electron - negative charge
5. Define atomic number and mass number.
atomic number - number of protons
mass number - mass of protons and neutrons
6. Identify what happens if we change the number of protons in an atom. Identify what happens if
we change the number of neutrons. Identify what happens if we change the number of
electrons.
if we change the number of protons then the element completely changes. the number of
protons determine the element on the periodic table. neutrons are neutral but if we change
the number of neutrons it becomes an isotope (same element, different number of neutrons).
if you change the electrons then it becomes an ion.
7. Define radioisotopes.
isotopes that contain an excess amount of neutrons, unstable and radioactive isotopes.
8. Describe the octet rule for the arrangement of electrons and how it applies to chemical stability.
Can 10 electrons be on the same level?
the octet rule is that only eight electrons can be in the outermost shell, only two in the first
innermost shell, and eight electrons in the outer shell = stability.
9. Describe ionic and covalent bonds. What happens if we put each in water?
ionic bonds - bonds between cations(postive charge) and anions (negative charge) bonded
together by electrostatic interaction. they are polar (like water)
covalent bonds - share electrons between two atoms and they are either polar or nonpolar.
create molecules
