MBMB techniques

Question 1

What is radioactivity?

Question 1

Describe the atomic structure

Answer 1

Composed of protons, neutrons and electrons. Protons are positively charged and located in the nucleus same as neutrons which are neutrally charged. Electrons are negatively charged and found around the nucleus in the shells.
No of protons = no of electrons
Atomic no (Z) = no of protons
Mass no (A) = no of protons (Z) + no of neutrons (N)
(A = Z+N)
No of neutrons (N) = A-Z

Question 2

Talk about the atomic nucleus and its relevance in radioisotopy

Answer 2

Is the central core of the atom
Radioactive processes are strictly nuclear phenomenon
Nuclear reactions involve mainly the nucleus – protons and neutrons
The electrons are responsible for chemical reactions

Question 2

Electrons are responsible for —— reactions

Answer 2

Chemical reactions

Question 3

What are isotopes?

Answer 3

Isotopes are different variations of an atom, having the same atomic number but different atomic mass. In essence, isotopes have the same proton number, but different neutron numbers.

Question 4

What are the three isotopes of hydrogen?

Answer 4

Hydrogen having one proton and one electron.

Deuterium have in one electron, one proton and one neutron.

Tritium have in one electron, one proton and two neutrons.

Question 5

What are the three isotopes of carbon?

Answer 5

Carbon 12 carbon 14 and carbon 13

Question 5

three Isotopes of oxygen

Answer 5

Oxygen 16
oxygen 17 and oxygen 18

Question 6

Atomic mass units

Answer 6

Unit used to measure the size of very small particles /atoms. Standard is carbon 12. Each proton and neutron is equal to one atomic mass unit.

Question 7

Formula for converting atomic mass units into grams

Answer 7

1 AMU is equal to 1.66×10 to the power of -24 g.

Question 8

What are isobars?

Answer 8

Isobars are atoms that share the same mass number, but different atomic number

Question 9

Two major differences between isotopes an isobars

Answer 9

Isotopes share the same atomic number, but different atomic mass.
They have different physical properties, but share the same chemical properties.

Isobars have different atomic numbers are the same mass number. They have different chemical and physical properties.

Question 10

What are radioisotopes?

Answer 10

Radioisotopes are defined as atoms that contain unstable nucleus and dissipate excess energy in their nucleus by spontaneously emitting radiations in the form of alpha, beta particles and gamma rays.
New elements are produced in the process. All the isotopes of elements with atomic number greater than 83 are radioactive.

Question 11

Nuclides

Answer 11

Basically just the nuclei of an atom, characterised by its atomic number, mass number or neutron number

Question 12

Isotones

Answer 12

Atoms of different elements having the same neutron number

Question 13

Unstable atomic nuclei

Answer 13

This occurs when when the strong nuclear force is not strong enough to overcome the repulsion of protons

Question 15

Radioactivity

Answer 15

The emission of energy by an unstable nuclei as it breaks down into a more stable form

Question 16

Two things that make a nuclei unstable

Answer 16

The size. A nuclei that is too big will become unstable. Any element with atomic number greater than 83 is unstable

An imbalance in the number of protons and neutrons. Isotopes with an uneven number of protons and neutrons are unstable.

Question 17

What is radioactive decay?

Question 18

Alpha emission

Question 19

Beta emission

Question 20

three. Types of radiation