Unit Checkpoint
Demonstrate mastery of chemistry basics concepts.
Checkpoint Questions
Question 1: What are the three subatomic particles and their charges?
Answer
Protons (positive), neutrons (neutral), electrons (negative).
Question 2: What does the atomic number of an element tell you?
Answer
The number of protons in an atom of that element.
Question 3: What is the difference between an atom and a molecule?
Answer
An atom is a single unit of an element. A molecule is two or more atoms bonded together.
Question 4: List two signs that a chemical reaction has occurred.
Answer
Examples: Color change, gas production, precipitate forms, temperature change, light produced.
Question 5: What type of bond involves sharing electrons?
Answer
Covalent bond.
Question 6: Where are electrons located in an atom?
Answer
Electrons are located in energy levels (shells) surrounding the nucleus.
Question 7: NaCl (table salt) has what type of bond?
Answer
Ionic bond. Sodium (metal) transfers an electron to chlorine (nonmetal).
Question 8: What is an ion?
Answer
An atom that has gained or lost electrons and has a net electrical charge.
Question 9: In a balanced chemical equation, what is conserved?
Answer
Mass is conserved. The number of atoms of each element is the same on both sides.
Question 10: Why are metals good conductors of electricity?
Answer
Metals have loosely held electrons that can move freely, allowing electrical current to flow.
Self-Assessment
- 8-10 correct: Excellent! Ready for next unit.
- 6-7 correct: Good! Review missed concepts.
- Below 6: Review lessons before continuing.