Biology 1 ______

Chapter 2NameHourScore

Table I. Elements that Make Up Living Things

Element / Symbol / % by Mass in Human Body / Element / Symbol / % by Mass in Human Body
Oxygen / O / 65.0 / Iron / Fe / trace
Carbon / C / 18.5 / Iodine / I / trace
Hydrogen / H / 9.5 / Copper / Cu / trace
Nitrogen / N / 33.3 / Manganese / Mn / trace
Calcium / Ca / 1.5 / Molybdenum / Mo / trace
Phosphorus / P / 1.0 / Cobalt / Co / trace
Potassium / K / 0.4 / Boron / B / trace
Sulfur / S / 0.3 / Zinc / Zn / trace
Sodium / Na / 0.2 / Fluorine / F / trace
Chlorine / Cl / 0.2 / Selenium / Se / trace
Magnesium / Mg / 0.1 / Chromium / Cr / trace

Directions

1Locate the positions of the most common elements that make up living things on the periodic table (see Table I). Use the periodic table in your text as your reference.

  1. Put only the atomic number and the symbol of the element in the appropriate box. You need only label the elements found in living things, NOT all the elements that exist.
  2. Use different colored pencils to color all the metals, nonmetals and metalloids in the table.

Key: / Metals / Color
Nonmetals / Color
Metalloids / Color

Types of Bonding: The Electron is always involved in a chemical bond.

4. Ionic Bond: Metals transfer electrons to non-metals. The resulting oppositely charged ions then attract each other and bond. The compound formed has no charge, so the total number of electrons lost by metal atoms must be equal to the total number of electrons gained by the non-metal atoms.

5. Covalent Bond: Non-metals bond with other non-metals by sharing electrons.

6. Metallic Bond: Metals bond with metals. (This is a type of bond that will never be discussed and has no function in biological systems)

Questions:

  1. What kind of bond would be formed between the following pairs of atoms?

Hint: Non-metal bonded to a Metal = Ionic Bond

Non-metal bonded to a Non-metal = Covalent Bond

  1. sodium and chlorine______

b.carbon and oxygen______

c.potassium and chlorine______

d.nitrogen and hydrogen______

e.carbon and nitrogen______

Table II. Complete the table.

Some metals give up just their outer energy level electrons to become positively charged ions.

Metal Atom / Symbol / Number of Protons / Number of electrons in an Energy Level of the Atom / Number of electrons lost / Charge on the ion
1st / 2nd / 3rd / 4th
calcium
magnesium
Na
19

Table III. Complete the table.

Many non-metals gain electrons from metals so that their outer energy level has eight electrons. When they gain electrons, they become negatively charged ions.

Non-Metal Atom / Symbol / Number of Protons / Number of electrons in an Energy Level of the Atom / Number of electrons gained / Charge on the ion
1st / 2nd / 3rd / 4th
chlorine
oxygen
16
N
F
5 / 0

Table IV. Complete the table.

Determine whether these common compounds have ionic bonds or covalent bonds and name them.

Compound / Name it / Ionic or Covalent Bonds
CO2
NaCl
H2O
O2