EmSAT EmSAT Physics 5

Question 1

What is the half-life of a radioactive substance?

Accepted Answer

The time for half the atoms to decay

Answer

Half-life is the time required for half of the radioactive atoms in a sample to decay. After one half-life, 50% remains; after two, 25%; and so on.

Question 2

Which type of radiation is most penetrating?

Accepted Answer

Gamma rays

Answer

Gamma rays are the most penetrating type of nuclear radiation. They are electromagnetic waves that can pass through most materials and require thick lead or concrete to block.

Question 3

What is nuclear fission?

Accepted Answer

Splitting a heavy nucleus into smaller nuclei

Answer

Nuclear fission is the process of splitting a heavy atomic nucleus (like uranium-235) into smaller nuclei, releasing a large amount of energy. It is the basis of nuclear reactors.

Question 4

What does E = mc² represent?

Accepted Answer

Mass-energy equivalence

Answer

Einstein's famous equation E = mc² expresses mass-energy equivalence: mass (m) can be converted to energy (E), and vice versa. c is the speed of light, making even small masses equivalent to enormous energy.

Question 5

What charge does a proton have?

Accepted Answer

Positive

Answer

A proton carries a positive charge of +1.6 × 10⁻¹⁹ coulombs. Neutrons are neutral and electrons are negatively charged.

EmSAT Practice Test

EmSAT Practice Test

EmSAT EmSAT Physics 5