15 Biology Final Exam Test Review (Chemistry)

Which of the following statements is true regarding the atomic number of an element?

• The atomic number is the number of protons in an element.
• The atomic number is the number of electrons in an element.
• The atomic number is the number of neutrons in an element.
• The atomic number is the mass of the nucleus of an element.

Silicon (Si) is in period 3 on the Periodic Table. What does this tell you about this element?

• It is highly reactive with water.
• It has 3 valence electrons.
• It has 3 protons in its nucleus
• It has 3 energy levels/shells in its electron cloud.

Mg + HCl → MgCl2 + H2

• Balanced
• Unbalanced

3C + 2Fe2O3 → 4Fe + 3CO2

• Balanced
• Unbalanced

Ba3N2 + 6H2O → 3Ba(OH)2 + 2NH3

• Balanced
• Unbalanced

6CO2 + 6H2O → C6H12O6 + 6O2

• Balanced
• Unbalanced

SnO2 + 2H2 → Sn + H2O2

• Balanced
• Unbalanced

If an element’s symbol contains two letters, the first letter is capitalized and the second letter is lower case.

• True
• False

The chemical formula for water is NaCl.

• True
• False

In a chemical formula, elements are represented by lower case letters and compounds are represented by capital letters.

• True
• False