Biology
Chapter 2 Chemistry of Life
Notes Outline 2-1
Section 1: Composition of Matter
I.
II.
III.
IV.
Picture: Jellyfish
a. The scientific name for the net-patterned jellyfish is _____________________________________.
b. An advantage that the jellyfish gains by living in water is _________________________ support.
c. All living things are made of the _________________ basic materials:
1. __________________
2. __________________
3. __________________
4. __________________
d. All living things are made of ________________ that are composed primarily of ________________.
e. The _________________________________ of life occur in the ____________________ environment of
the cell.
Introduction - The structure and function of all living things are governed by the laws of ___________________.
Matter
a. __________________ in the universe is made of matter.
b. __________________ is anything that occupies space and has mass.
c. __________________ measures the amount of matter in an object.
d. __________________ is the measure of the force produced by gravity acting on a mass.
e. Mass and weight are not the ____________________.
1. The force of gravity on the moon is ________ the force of gravity on the Earth.
2. An object with a mass of 100 grams on Earth would have a mass of _______ grams on the moon.
3. An object that weighs 100 lb on Earth would weigh about ______ lb on the moon.
Elements and Atoms
a. Introduction
1. ____________________ are substances that cannot be broken down chemically into simpler
kinds of matter.
i.
There are ______ naturally occurring elements in nature.
ii.
Today, there are ______ elements on the periodic table.
iii.
There are ______ elements that are essential to living things.
iv.
More than _______ of the mass of all living things is composed of compounds made up
of oxygen, carbon, hydrogen, and nitrogen.
2. Elements are arranged in a chart known as the _________________________.
i.
Each element has a different chemical ____________________ that consists of one,
two, or three letters. Example, K, He, and Uuq.
ii.
Most symbols are derived from the ______________ letter(s) in the name of the
element. Example, the symbol for chlorine is ______.
iii.
Some symbols are derived from the ______________ names of elements. Example,
sodium’s symbol is ______, which comes from the word ________________.
3. The simplest particle of an element that retains (keeps) all the properties of that element is an
___________________.
i.
Atoms are so small that their structures cannot be _________________ observed.
ii.
Scientists developed ___________________ that describe the structure of an atom.
b. The Nucleus
1. The central region, or ____________________, makes up the bulk of the mass of an atom.
2. The nucleus is made up of two types of subatomic particles:
i.
____________________ - positively charged particle
ii.
____________________ - particle with no charge
3. The number of protons in an atom is called the _____________________________.
i.
No two elements have the _______________ atomic number.
ii.
Example, fluorine is element number 9 on the periodic table, and it has _____ protons.
V.
4. The total number of protons and neutrons in the nucleus is called the _____________________.
i.
The mass number of fluorine is 19. Therefore, it has 9 protons and _____ neutrons in
the nucleus.
c. Electrons
1. In an atom, the number of positively charged protons are balanced by an ______________
number of small, negatively charged ___________________.
2. The net (overall) electrical charge of an atom is _________________.
3. Electrons have very little ____________. They are about ___________ times smaller than
protons and neutrons.
4. Electrons move about the nucleus at very high _______________.
5. Electrons are located outside the nucleus in regions called _________________.
6. Electrons in orbitals closer to the nucleus have _______________ energy than electrons located
in orbitals farther from the nucleus.
7. All the orbitals and their electrons make up the ____________________________.
8. The electron cloud is mostly ______________________________.
9. Example, if the nucleus of an atom is represented by a __________ in centerfield at Turner Field,
the electrons would be represented by a few __________ buzzing around the stadium.
d. Isotopes
1. All atoms of the same element have the same number of _____________________.
2. However, all atoms of the same element do not necessarily have the same number of
________________________.
3. Atoms of the same element that have different numbers of neutrons are called _____________.
4. Additional neutrons change the ________________________ of the element.
Compounds
a. Introduction
1. Most elements in nature do not exist ___________________; most elements can readily
combine with the same or different atoms or elements to make ____________________.
2. Compounds are made up of two or more elements in _______________ proportions.
3. A chemical _________________ shows the proportion of atoms of each element in the
compound. Example, water has a chemical formula of H2O. Water always consists of ____
hydrogen atoms and ____ oxygen atom.
4. The physical and chemical properties ________________ between elements and the
compounds they form. Example, hydrogen and oxygen are _______________ in nature, but they
combine to form a __________________.
5. An atom is chemically _______________ when the orbitals in its highest energy level are filled.
These atoms do not react to other elements and are called _____________ or _____________
elements.
6. __________________________ are the attractive forces that hold atoms together.
b. Covalent Bonds
1. ___________________ bonds form when two atoms ______________ pairs of electrons.
2. A ____________________ is the simplest part of a substance that retains all the properties of
that substance and can exist in a free state.
c. Ionic Bonds
1. A substance with an electrical charge is called an ______________.
2. ___________________ bonds form when atoms gain or lose electrons to fill the outermost
energy level.
i.
Positive ions are called ___________________.
ii.
Negative ions are called __________________.
Assignment:
Answer the SECTION 1 REVIEW Questions #1-9 page 34.