Radioactive decay

How many protons are in this atom?

• 3
• 4
• 6
• 10

Tags

NGSS.MS-PS1-1

How many neutrons are in this isotope of Uranium?

• 235
• 92
• 327
• 143

Tags

NGSS.HS-PS1-8

The half-life of Zn-71 is 2.4 minutes. Starting with 100.0 g, how many grams would remain after 4.8 minutes (2 half-lives)?

• 100.0 g

• 50.0 g

• 25.0 g

• 8.5 g

Tags

NGSS.HS-PS1-8

What is likely to happen to unstable nuclei with too many, or too few, neutrons?

• They will decay by emitting radiation.

• They will loose all their electrons.

• They will bond with other atoms.

Tags

NGSS.HS-PS1-8

After how many half-lives would you only have 12.5% of the original isotope left?

• 1

• 2

• 3

• 4

Tags

NGSS.HS-PS1-8

What percentage of the original isotope is left after 1 half-lives?

• 100%

• 75%

• 50%

• 25%

Tags

NGSS.HS-PS1-8

What percentage of the original isotope is left after 2 half-lives?

• 100%

• 75%

• 50%

• 25%

Tags

NGSS.HS-PS1-8

The half-life of a substance is 6000 years. How long would it take for half the substance to change from a radioactive isotope to a stable substance?

• 3000

• 6000

• 9000

• 12000

Tags

NGSS.HS-PS1-8

Carbon dating is used to determine the age of a fossil. Less than 7% of the original amount of radioactive carbon-14 is left. How many half-lives would have passed?

• 1

• 2

• 3

• 4

Tags

NGSS.HS-PS1-8

Carbon dating is used to determine the age of a fossil. About 80% of the original amount of radioactive carbon-14 is left. How many half-lives would have passed?

• less than 1

• more than 2

• about 3

• exactly 4

Tags

NGSS.HS-PS1-8