Essential Questions
1. In what ways does the unique properties of helium set it apart from other chemical elements?
2. How was the discovery of helium made both on Earth and in the universe?
3. What is the relative abundance of helium compared to other elements in the universe?
4. What are the isotopes of helium and what factors contribute to their stability?
5. How is helium produced on Earth and what processes are involved?
6. Why does helium not accumulate in significant quantities in the atmosphere despite its abundance in the universe?
Learning Objectives
1. Understand the abundance and distribution of helium in the universe 2. Explain the role of radioactive decay in the generation of helium 3. Explain the discovery of helium
4. Explain why helium does not accumulate in large quantities in the atmosphere 5. Understand the relationship between helium-3 and hydrogen-3 isotopes 6. Identify the properties of helium
7. Recognize the isotopes of helium and their stability 8. Define the structure of a helium atom
9. Understand the concept of alpha particles and their relation to helium Questions
1. How does helium's abundance in Earth's atmosphere compare to hydrogen?
A. Helium is less abundant than hydrogen B. Helium is not present in Earth's atmosphere C. Helium is more abundant than hydrogen D. Helium and hydrogen have equal abundance
○ Correct answer: A. Helium is less abundant than hydrogen 2. What is the role of radioactive decay in the generation of helium?
A. It generates helium as a byproduct B. It destroys helium atoms
C. It converts helium into hydrogen D. It creates helium from hydrogen
○ Correct answer: A. It generates helium as a byproduct
3. Who discovered helium in the gaseous atmosphere surrounding the Sun?
A. Edward Frankland B. Joseph Norman Lockyer C. Pierre Janssen
D. William Ramsay
○ Correct answer: C. Pierre Janssen
4. Why does helium not accumulate in large quantities in the atmosphere?
A. It is absorbed by the oceans B. It is consumed by plants
C. Earth's gravity is not sufficient to prevent its escape into space D. It reacts with oxygen in the air
○ Correct answer: C. Earth's gravity is not sufficient to prevent its escape into space 5. What is the second most abundant element in the cosmos after hydrogen?
A. Oxygen B. Nitrogen C. Helium D. Carbon
○ Correct answer: C. Helium
6. What is the relationship between helium-3 and hydrogen-3 isotopes?
A. They are the same element
B. Helium-3 is a rare isotope of hydrogen-3 C. Helium-3 is a byproduct of hydrogen-3 decay D. Helium-3 decays into hydrogen-3
○ Correct answer: B. Helium-3 is a rare isotope of hydrogen-3 7. What is the boiling and freezing point of helium?
A. -268.9 °C (-452 °F) B. -200 °C (-328 °F) C. -100 °C (-148 °F) D. 0 °C (32 °F)
○ Correct answer: A. -268.9 °C (-452 °F) 8. Which isotopes of helium are stable?
A. Helium-1 and Helium-2 B. Helium-3 and Helium-4 C. Helium-5 and Helium-6
D. Helium-7 and Helium-8
○ Correct answer: B. Helium-3 and Helium-4
9. How many protons are present in the nucleus of a helium atom?
A. One B. Four C. Three D. Two
○ Correct answer: D. Two 10. What are alpha particles?
A. Electrons B. Neutrons C. Protons D. Helium nuclei
○ Correct answer: D. Helium nuclei