The technetium-99 isotope has a half-life of 6.0 hours. If 100.0 mg were injected into a patient how much remains after 18 hours?

• 33.0 mg

• 12.5 mg

• .33 mg

• 15.8 mg

In a correctly written symbol what would be located in the "A" position?

• number of neutrons
• atomic number
• number of electrons 
• mass number

How many protons are in this atom?

• 3

• 4

• 6

• 10

What is the name of the pictured isotope?

• Copper-29

• Copper-63

• Copper-34

• Copper-43

Rubidium-87 with atomic number of 37 gives off a beta particle. What will be the resulting isotope?

• Br-85 with atomic number of 35

• Strontium-87 with atomic number of 38

• Yttrium-87 with atomic number of 39

• Kr-87 with atomic number of 36

These three isotopes of carbon have different -

• Atomic numbers

• Mass numbers

• Numbers of protons

• Symbols

How many neutrons are in this isotope of Uranium?

• 235
• 92
• 327
• 143

Which type of nuclear radiation is being emitted here?

• Alpha
• Beta
• Gamma 
• none

What is meant by the statement that ³²₁₅P has a half life of 14 days

• It takes 7 days to go down to 50% radioactivity each time

• It takes 14 days to go down to 50% radioactivity each time

• After 14 days it starts to become less radioactive

• It takes 14 days to go up by 50% radioactivity each time

How is carbon-12 different from carbon-14?

• They have a different number of protons 
• They have a different number of electrons
• They have a different number of neutrons
• They are different elements