Year 9 science half-life questions

Consider a 5 kg radioactive sample that has a half life of 5 days. How much of this sample is left after 15 days?

• 625 g

• 0.33 kg

• 62.5 g

• 2500 g

Tags

NGSS.HS-PS1-8

What is the half life of an element if one-eight of the original is left after 120 years?

• 40 years

• 60 years

• 90 years

• 30 years

Tags

NGSS.HS-PS1-8

An element has a half-life of 12 days. A 3kg block of the element is left to decay, how much will be left after 36 days?

• 375 g

• 187.5 g

• 900 g

• 83.33 g

Tags

NGSS.HS-PS1-8

This graph shows the radioactive decay of strontium-90. What is its half-life?

• About 25 years

• About 15 years

• About 115 years

• About 85 years

Tags

NGSS.HS-PS1-8

This graph shows the radioactive decay of strontium-90. After 55 years, how much will be left?

• 0.25 kg

• 0.5 kg

• 0.125 kg

• 0.75 kg

Tags

NGSS.HS-PS1-8

What is the half life of an element if one-quarter of the original is left after 240 years?

• 120 years

• 60 years

• 90 years

• 140 years

Tags

NGSS.HS-PS1-8

This isotope is frequently used in nuclear reactors. What is its mass number?

• 92

• 235

• 327

• 143

Tags

NGSS.HS-PS1-8

This isotope is frequently used in nuclear reactors. What is its atomic number?

• 92

• 235

• 327

• 143

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-8

This isotope is frequently used in nuclear reactors. How many neutrons does it have?

• 92

• 235

• 327

• 143

Tags

NGSS.HS-PS1-8

Which type of nuclear radiation has the highest penetrating power and is the most dangerous to living tissues?

• alpha particles

• beta particles

• gamma rays

• X rays

Tags

NGSS.HS-PS4-4