Isotopes and nuclear chemistry practice

What does it mean when an element is radioactive?

• atom emits radiation
• nucei unstable due to uneven p to n ratio
• nuclei changes to become stable
• all of the above

Tags

NGSS.HS-PS1-8

The time taken for half of an amount of radioactive atoms to decay.

• Nuclear fusion
• Full-life
• Dead time
• Half-life

Tags

NGSS.HS-PS1-8

How many protons are in this atom?

• 3
• 4
• 6
• 10

Tags

NGSS.MS-PS1-1

How are these isotopes different?

• Different atomic numbers
• Different number of protons
• Different number of neutrons
• Different number of electrons

Tags

NGSS.HS-PS1-8

What is the Atomic mass of an isotope that has 20 protons, 21 neutrons and 18 electrons?

• 18

• 20

• 21

• 41

In what part of an atom can protons be found? 

• Inside the electrons
• Inside the neutrons 
• Inside the atomic nucleus 
•  Inside the electron shells

Tags

NGSS.HS-PS1-8

What do carbon-12 and carbon-14 have in common? 

• They have the same number of protons
• They have the same number of neutrons
•  They have the same atomic mass
• They have the same atomic weight

Tags

NGSS.HS-PS1-8

What makes something radioactive?

• elements with an atomic number above 81
• an unstable nucleus
• contaminated sewage
• It decays over time

Tags

NGSS.HS-PS1-8

If the half life of a radioactive element is 100yrs, how long would it take for the radioactivity to reduce by one half?

• 200yrs
• 100yrs
• 50yrs
• 300yrs

Tags

NGSS.HS-PS1-8

The radioactive isotope Nickel-63 has a half life of 10 years. How much of a 1000 gram sample remains after 30 years?

• 1000 gram

• 125 grams

• 500 grams

• 2500 grams