IB phys II - week of 3/2 - ch 7.1-7.2

Krypton-85 is used in indicator lights of appliances. The half-life of krypton-85 is 11 years. How much of a 2.000 mg sample remains after 33 years?

• 1 mg

• 0.5 mg

• 0.25 mg

• 0.125 mg

How many protons and neutrons does the hydrogen-2 isotope contain?

• 1 proton, 0 neutrons

• 2 protons, 0 neutrons

• 0 protons, 2 neutrons

• 1 proton, 1 neutron

What causes nuclear reactions to produce energy?

• mass defect

• binding energy

• breaking of chemical bons

• nuclear reactions do not produce energy

Classify the following nuclear reaction.

Carbon-12 reacts with hydrogen-1 to produce nitrogen-13 and a gamma particle.

• fission

• fusion

• radioactive decay

• alpha particle emission

What does the mass number represent?

• protons

• neutrons

• protons & neutrons

• protons & electrons