Unit 1.1

Question 1

What particles are found in the nucleus of an atom?

Answer 1

Protons and neutrons.

Question 2

What is the charge of electrons?

Answer 2

Negatively charged.

Question 3

What does the atomic number represent?

Answer 3

The number of protons in the nucleus.

Question 4

How is the mass number of an atom calculated?

Answer 4

By adding the number of protons and neutrons in the nucleus.

Question 5

What is an isotope?

Answer 5

Atoms of the same element that have different numbers of neutrons.

Question 6

What happens to the atomic number during alpha decay?

Answer 6

It decreases by 2.

Question 7

What is emitted during alpha decay?

Answer 7

An alpha particle, which consists of 2 protons and 2 neutrons.

Question 8

What is the chemical symbol for an alpha particle?

Answer 8

He.

Question 9

What is the effect of beta decay on the atomic number?

Answer 9

It increases by 1.

Question 10

What is emitted during beta decay?

Answer 10

A fast-moving electron.

Question 11

What happens to the mass number during beta decay?

Answer 11

It remains unchanged.

Question 12

What is the relationship between the total atomic number and mass number before and after radioactive decay?

Answer 12

They remain the same on both sides of the decay equation.

Question 13

What element does uranium-238 decay into during alpha decay?

Answer 13

Thorium-234.

Question 14

What is the formula for the decay of uranium-238 into thorium-234?

Answer 14

238U → 234Th + He.

Question 15

What is the process called when heavy elements undergo transformation into lighter elements?

Answer 15

Radioactive decay.

Question 16

What does subtracting the atomic number from the mass number yield?

Answer 16

The number of neutrons in the nucleus.

Question 17

What is the notation for a beta particle in equations?

Answer 17

e.

Question 18

What happens to a neutron during beta decay?

Answer 18

It breaks up into a proton and an electron.

Question 19

What is induced fission?

Answer 19

Induced fission occurs when neutrons bombard another nuclei, causing them to split and produce energy.

Question 20

What is the relationship between mass and energy in nuclear reactions?

Answer 20

Energy is produced through the conversion of mass into energy, as described by the equation E = mc².

Question 21

What does E = mc² represent?

Answer 21

E is energy in joules, m is change in mass in kilograms, and c is the speed of light in meters per second.

Question 22

What is nuclear fusion?

Answer 22

Nuclear fusion is the reaction where two small nuclei combine to form a larger nucleus, releasing energy.

Question 23

What is the mass defect?

Answer 23

The mass defect is the difference between the mass of a nucleus and the sum of the masses of its constituent nucleons.

Question 24

How is energy calculated in fission and fusion reactions?

Answer 24

The energy released is calculated from the difference in mass between the reactants and products.

Question 25

What must be balanced in fission and fusion equations?

Answer 25

The total number of neutrons and protons must be the same on both sides of the equation.

Question 26

What is spontaneous fission?

Answer 26

Spontaneous fission occurs without external influence, as opposed to induced fission.

Question 27

What happens to the mass of products in fission and fusion reactions?

Answer 27

The mass of the products is less than the mass of the starting materials due to mass being converted into energy.

Question 28

What role do neutrons play in nuclear reactors?

Answer 28

Neutrons produced in fission reactions initiate further fissions, sustaining the reaction.

Question 29

What is the primary reaction that occurs in the Sun?

Answer 29

Nuclear fusion of hydrogen nuclei into helium.

Question 30

What is the significance of the equation E = mc² in nuclear physics?

Answer 30

It shows the equivalence of mass and energy, fundamental to understanding nuclear reactions.

Question 31

What type of energy is produced in nuclear fission?

Answer 31

Nuclear fission produces thermal energy, which can be converted into electrical energy.

Question 32

What is the outcome of a fission reaction?

Answer 32

A fission reaction produces smaller nuclei, neutrons, and energy.

Question 33

What is the difference between fission and fusion?

Answer 33

Fission splits large nuclei into smaller ones, while fusion combines small nuclei into a larger one.

Question 34

What is the role of energy in nuclear reactions?

Answer 34

Energy is released when mass is converted during fission or fusion.

Question 35

What is the first step in calculating the energy released by a nuclear reaction?

Answer 35

Finding the difference in mass between each side of the equation.

Question 36

How do you calculate the difference in mass for the fission reaction?

Answer 36

Subtract the total mass on the right from the total mass on the left.

Question 37

What equation is used to calculate the energy released from the change in mass?

Answer 37

E = mc^2

Question 38

What process do current nuclear power stations use to produce energy?

Answer 38

Nuclear fission

Question 39

What is the primary goal of scientists working on nuclear fusion?

Answer 39

To use nuclear fusion to provide energy.

Question 40

What must hydrogen atoms achieve to form helium in a fusion reactor?

Answer 40

Very high temperatures (about 100,000,000 K) and high pressure.

Question 41

What methods are used to heat hydrogen plasma in fusion reactors?

Answer 41

Microwaves, electricity, and neutral particle beams from accelerators.

Question 42

What role do superconducting magnets play in fusion reactors?

Answer 42

They hold the hydrogen plasma in suspension.

Question 43

What happens if the plasma in a fusion reactor contacts the container?

Answer 43

It could melt the walls and the plasma would lose energy.

Question 44

How is the heat energy generated by the fusion process utilized?

Answer 44

It is used by heat exchangers to convert water to steam, driving generators to produce electricity.