What unit is radioactivity NOT measured in?

Count Rate

Is an isotope has an atomic number of 92 and a mass number of 196, what is the number of neutrons?

104

What is the term used to describe the actual mass of an atom?

Atomic Weight

How much radioactivity is left?
Initial Activity- 6 Ci of Sr-90
Time Elapsed- 16 years, 3 months
Half Life- 28.8 years

4.06 Curies

How much radioactivity is left?
Initial Activity- 17 Ci of Cf-252
Time Elapsed- 6 years, 7 months
Half Life- 2.6 years

2.87 Curies

What is the term used to describe the number of protons in the nucleus of an atom?

Atomic Number

What is the term used to describe the number of protons and neutrons in the atom?

Atomic Mass

Match the atomic particles with their respective charges.

Electron- Negative
Nucleus- Neutral
Proton- Positive

If uranium has 92 protons and an isotope has 143 neutrons, what is the mass number of the isotope?

235

How much radioactivity is left?
Initial Activity- 310 Ci of Co-60
Time Elapsed- 12 years, 2 months
Half Life- 5.27 years

62.6 Curies

How much radioactivity is left?
Initial Activity- 8 Ci of Cs-137
Time Elapsed- 21 years, 4 months
Half Life- 30 years

4 Curies (might be wrong, sorry!)

What is the term used to describe the time required for the activity present in a radioactive material to be reduced to one half of the original activity?

Half Life