Isotopes

• What are the three subatomic particles that make up an atom?

  Protons, neutrons, and electrons
• What happens to an atom when the number of neutrons changes?

  It becomes an isotope
• What occurs when the number of electrons in an atom changes?

  It becomes an ion
• What defines an element's atomic number?

  • The number of protons in the nucleus
• What element has 17 protons?

  Chlorine
• How does an element's mass number vary?

  It can have different numbers of neutrons
• What is the usual mass number of chlorine?

  35
• How many neutrons does chlorine usually have if its mass number is 35?

  18 neutrons
• What is the mass number of a chlorine isotope that has 20 neutrons?

  37
• What are isotopes?

  • Forms of an element with the same number of protons
  • Different numbers of neutrons
• How many isotopes of hydrogen are there?

  Three

  
• What are the names of the isotopes of hydrogen?

  Hydrogen, deuterium, and tritium

  
• What are the isotopes of carbon?

  ¹²C, ¹³C, and ¹⁴C
• How many protons does ¹⁴C contain?

  Six protons
• How many neutrons does ¹⁴C contain?

  Eight neutrons
• Why are ¹⁴N and ¹⁴C not considered isotopes?

  They are not the same element
• What is the atomic number of carbon?

  Six
• What is the relationship between protons and elements?

  • The number of protons determines the element
  • Changing the number of protons results in a different element
• What is the significance of the atomic number in identifying an element?

  It uniquely identifies the element