Atomic and nuclear processes

Question 1

nucleus

Answer 1

small, dense region consisting of protons and neutrons at the centre of the atom. Protons are positively charged and neutrons are electrically neutral.

Question 2

quarks

Answer 2

form composite particles called hadrons, such as protons and neutrons. All observable matter is made of up quarks, down quarks and electrons

Question 3

proton in quarks

Answer 3

two up quarks and one down quark

Question 4

neutron in quarks

Answer 4

one up quark and two down quarks

Question 5

nuclear fusion

Answer 5

two or more nuclei are combined with high energy and temperature, to form different atomic nuclei. This process releases vast amounts of energy.

Question 6

nuclear fission

Answer 6

heavy isotopes are split apart when unstable, into two smaller and more stable nuclei

Question 7

nuclear decay

Answer 7

Random process where a nucleus loses energy by emitting radiation

Question 8

alpha

Answer 8

helium nuclei, 2 protons and 2 neutrons

Question 9

beta

Answer 9

electrons or positrons, proton -1 and neutrons 0

Question 10

gamma

Answer 10

high energy photons, high energy wave

Question 11

activity

Answer 11

number of decays per second in a given sample

Question 12

alpha decay

Answer 12

alpha particle given off, neutrino given off

Question 13

beta + decay

Answer 13

releases a positively charged beta particle (positron) and a neutrino.

Question 14

beta - decay

Answer 14

releases an electron and an antineutrino

Question 15

gamma decay

Answer 15

The nucleus goes from a high energy state to a lower energy state through the emission of electromagnetic radiation (photons). The proton and neutron number don’t change, so the parents and daughter atoms are the same element.

Question 16

atomic mass unit

Answer 16

It is defined as 1/12 of the mass of an unbound neutral atom of carbon-12 in its nuclear and electronic ground state and at rest

Question 17

background radiation

Answer 17

measure of the level of ionizing radiation present in the environment at a particular location which is not due to deliberate introduction of radiation sources. Background radiation originates from a variety of sources, both natural and artificial

Question 18

fission

Answer 18

Heavy and unstable isotopes are split apart into two smaller nuclei and gives off energy

Question 19

fusion

Answer 19

The combination of two or more particles to form different atomic nuclei

Question 20

half life

Answer 20

The time taken for radiation to decay by half

Question 21

radioactive dating

Answer 21

technique which is used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed.

Question 22

chain reaction

Answer 22

process in which neutrons released in fission produce an additional fission in at least one further nucleus. This nucleus in turn produces neutrons, and the process repeats