CART Nuclear Chemistry and Radioactivity 3

Question 1

Einstein's equation E = mc² relates mass and energy in nuclear reactions. What does 'c' represent?

Accepted Answer

The speed of light in a vacuum

Answer

In E = mc², c is the speed of light (~3 × 10⁸ m/s); because c² is enormous, even tiny mass losses produce vast amounts of energy.

Question 2

Nuclear fusion requires extremely high temperatures primarily because:

Accepted Answer

High temperature provides energy to overcome the electrostatic repulsion between positively charged nuclei

Answer

Positively charged nuclei repel each other (Coulomb repulsion); extremely high kinetic energy (temperature) is needed for them to get close enough for the strong nuclear force to fuse them.

Question 3

Which type of radiation is stopped most easily and cannot penetrate human skin?

Accepted Answer

Alpha particles

Answer

Alpha particles are large, heavy, and doubly charged; they lose energy quickly and are stopped by a few centimeters of air or a sheet of paper.

Question 4

The nuclear binding energy of a nucleus represents:

Accepted Answer

The energy required to completely separate a nucleus into its individual protons and neutrons

Answer

Nuclear binding energy is the minimum energy needed to disassemble a nucleus into its constituent free protons and neutrons; it reflects nuclear stability.

Question 5

Positron emission (beta-plus decay) results in:

Accepted Answer

A decrease in atomic number by 1

Answer

In positron emission, a proton converts to a neutron, so the atomic number decreases by 1 while the mass number stays the same.

CART - Chemistry Acceleration Readiness Test Practice Test

CART - Chemistry Acceleration Readiness Test Practice Test

CART Nuclear Chemistry and Radioactivity 3