1. Which of the following is NOT one of the four most common elements in your body?
a) carbon.
b) nitrogen.
c) hydrogen.
d) iron.
e) oxygen.

2. What two elements are the most abundant in the Universe?
a) carbon and oxygen.
b) carbon and nitrogen.
c) hydrogen and helium.
d) carbon and hydrogen.
e) iron and oxygen.

3. A ¹³C atom contains:
a) 6 protons, 13 neutrons.
b) 7 protons, 6 neutrons.
c) 13 protons, 13 neutrons.
d) 13 protons, 0 neutrons.
e) 6 protons, 7 neutrons.

4. What is a positron?
a) a positively-charged electron.
b) a positively-charged proton.
c) an anti-proton.
d) a microwave.
e) a positively-charged neutron.

5. When an electron and a positron collide, they produce:
a) gamma rays.
b) a proton.
c) a neutron.
d) a deuterium atom.
e) radio waves.

6. The Second Law of Thermodynamics states:
a) E = mc².
b) N = R_*f_pn_ef_lf_if_c.
c) energy is always conserved.
d) the entropy of a closed system always increases or remains the same.
e) atomic mass = number of protons + number of neutrons.

7. An Astronomical Unit is:
a) The distance from the earth to the Sun.
b) The distance from the Sun to alpha Centauri.
c) A light year.
d) A solar mass.
e) The diameter of the Milky Way.

8. The number of galaxies in the Universe is:
a) About 3 dozen.
b) 6.5 billion.
c) About 1500.
d) About 400 thousand.
e) More than 45 billion.

9. The two most common types of atoms in the Universe are:
a) carbon, oxygen.
b) hydrogen, helium.
c) hydrogen, carbon.
d) oxygen, nitrogen.
e) hydrogen, carbon.

10. The Drake Equation:
a) Describes the rate of expansion of the Universe.
b) Gives an estimate of the number of advanced civilizations currently in the Milky Way.
c) Describes the nuclear reactions in the early Universe.
d) Gives an estimate of the temperature of the early Universe.
e) Gives an estimate of the number of humans on Earth.

11. Deuterium is:
a) ¹H.
b) ²H.
c) ²He.
d) ⁴He.
e) Neutral subatomic particles with masses less than 1/2000th that of an electron.

12. A ¹³N⁺ atom has:
a) 13 protons, 13 neutrons, 12 electrons.
b) 6 protons, 7 neutrons, 5 electrons.
c) 7 protons, 6 neutrons, 6 electrons.
d) 7 protons, 7 neutrons, 6 electrons.
e) 7 protons, 6 neutrons, 8 electrons.

13. The Sun is:
a) 4.3 light minutes away.
b) 4.3 light years away.
c) 8.3 light minutes away.
d) 8.3 light years away.
e) 8.3 A.U. away.

14. When the Universe was very young, the light that we now call the cosmic microwave background radiation was mainly:
a) radio waves.
b) visible light.
c) X-rays.
d) infrared light.
e) gamma rays.

15. Extrasolar planets:
a) Have not yet been discovered, but astronomers are hoping to discover some in the next few decades.
b) Are orbiting the Sun outside the orbit of Pluto.
c) Are planets that have been found orbiting other stars besides the Sun.
d) Can be seen without a telescope from Earth, at a dark site.
e) Are found by studying the light from distant galaxies.

16. A helium-4 nucleus contains:
a) 4 protons and 4 neutrons.
b) 2 protons and 2 neutrons.
c) 4 neutrons and 0 protons.
d) 2 positrons and 2 electrons.
e) 4 hydrogen atoms.

17. A light year is:
a) The distance to the closest star besides the Sun divided by 4.3.
b) The distance to the closest star besides the Sun.
c) The distance to the Sun.
d) 93 million miles = 150 million kilometers.
e) 5.2 Astronomical Units.

18. The distance from the Earth to alpha Centauri is:
a) an astronomical unit (A.U.).
b) 4.3 astronomical units (4.3 A.U.).
c) 8.3 light minutes.
d) 4.3 light years.
e) 150,000 light years.

19. The number 50,000,000 can be written:
a) 5 X 10^-7.
b) 5 X 1⁷.
c) 5 X 10⁷.
d) 5⁷
e) 5 billion.

20. What is the correct order of the following types of light, in terms of their frequency, from SMALLEST to LARGEST?
a) radio, infrared, red, green, ultraviolet, X-rays.
b) X-rays, ultraviolet, green, red, infrared, radio.
c) X-rays, infrared, green, red, ultraviolet, radio.
d) radio, ultraviolet, red, green, infrared, X-rays.
e) X-rays, radio, ultraviolet, infrared, red, green.

21. The highest energy type of light is:
a) radio waves.
b) visible light.
c) X-rays.
d) infrared light.
e) gamma rays.

22. Primordial nucleosynthesis lasted:
a) less than about 1 second.
b) less than about 30 minutes.
c) 1000 years.
d) 500 thousand years.
e) a billion years.

23. In the very early Universe, when a proton and neutron fused, they formed:
a) an electron.
b) a ¹H atom.
c) a ²H atom.
d) a ³He atom.
e) a ⁴He atom.

24. The Universe is becoming more disordered with time. This law is called:
a) the Drake relation.
b) the Scientific Method.
c) the First Law of Physics.
d) the Second Law of Thermodynamics.
e) the biosphere law.

25. The three most common types of atoms in a human body are:
a) hydrogen, carbon, oxygen.
b) hydrogen, helium, lithium.
c) carbon, oxygen, nitrogen.
d) oxygen, nitrogen, neon.
e) carbon, iron, magnesium.

26. An atom with more protons than electrons is called:
a) an isotope.
b) a positron.
c) deuterium.
d) a gamma ray.
e) an ion.

27. The lowest energy type of light is:
a) radio waves.
b) visible light.
c) X-rays.
d) infrared light.
e) gamma rays.

28. The type of light with wavelengths between those of X-rays and visible light is:
a) gamma rays.
b) infrared.
c) ultraviolet.
d) radio waves.
e) microwaves.

29. Two atoms with the same number of protons and electrons, but different numbers of neutrons, are called:
a) isotopes.
b) ions.
c) ionized.
d) molecules.
e) different chemical elements.

30. The early Universe was filled with:
a) iron.
b) water.
c) nitrogen gas.
d) methane and ammonia.
e) light.

31. To fill its outer electron shell, nitrogen shares how many pairs of electrons with other atoms?
a) none.
b) one.
c) two.
d) three.
e) four.

32. The mass of a deuterium atom is approximately:
a) the same as that of a proton.
b) twice that of a proton.
c) twice that of an electron.
d) four times that of a proton.
e) six times that of a proton.

33. Evidence for the Big Bang theory includes:
a) The expansion of the Universe.
b) The cosmic microwave background.
c) The observed abundances of ¹H, ²H, ³He, ⁴He, Li.
d) All of the above.
e) None of the above.

34. The Drake Equation begins with `N = '. The `N' stands for:
a) The number of galaxies in the Universe.
b) The number of people on Earth.
c) The number of advanced civilizations now in the Milky Way.
d) The number of stars in the Milky Way.
e) The average number of planets per solar system.

35. If there were an advanced civilization on a planet orbiting around alpha Centauri A, how long would it take to send a radio signal to them, and get a response?
a) 8.3 minutes.
b) 16.6 minutes.
c) 8.6 years.
d) 1000 years.
e) 2 million years.

36. Neon generally doesn't make molecular bonds because:
a) it has an even number of protons.
b) it has a full outer shell of electrons.
c) it has the same number of neutrons as protons.
d) it has the same number of electrons as protons.
e) it is the lowest mass chemical element.

37. When a proton and an anti-proton collide, they produce:
a) gamma rays.
b) an electron.
c) a neutron.
d) a deuterium atom.
e) radio waves.

38. The light in the early Universe was mostly:
a) radio waves.
b) microwaves.
c) infrared light.
d) ultraviolet light.
e) gamma rays.

39. A theory is:
a) a guess.
b) a hypothesis.
c) a hypothesis that has been tested again and again, and not disproven.
d) a fact.
e) definitely true.

40. A ¹⁵N atom contains:
a) 7 protons, 15 neutrons.
b) 15 protons, 15 neutrons.
c) 7 protons, 8 neutrons.
d) 8 protons, 7 neutrons.
e) 15 protons, 0 neutrons.

41. A positively-charged electron is called:
a) a positron.
b) a proton.
c) a neutron.
d) an ion.
e) an alpha particle.

42. The last term in the Drake Equation is `L'. This stands for:
a) The age of the Universe.
b) The length of time that primordial nucleosynthesis lasted.
c) The size of the Universe.
d) The size of a light year.
e) The average lifetime of an advanced civilization.

43. Only two electrons can fit in the innermost shell of electrons in an atom. How many can fit in the second electron shell?
a) two.
b) four.
c) six.
d) eight.
e) eighteen.

44. The mass of an electron is:
a) zero.
b) 1/2000th that of a proton.
c) equal to that of a proton.
d) equal to that of a neutron.
e) 2000 times that of a proton.

Answers: 1d, 2c, 3e, 4a, 5a, 6d, 7a, 8e, 9b, 10b, 11b, 12c, 13c, 14e, 15c, 16b, 17a, 18d, 19c, 20a, 21e, 22b, 23c, 24d, 25a, 26e, 27a, 28c, 29a, 30e, 31d, 32b, 33d, 34c, 35c, 36b, 37a, 38e, 39c, 40c, 41a, 42e, 43d, 44b.