atomic structure and particle physics

Question 1

plum pudding model of the atom

Answer 1

a model that pictured that atom as a positive sphere of pudding with small negatively charged plums with small negatively charged plums embedded in it

Question 2

nuclear model of atom

Answer 2

a model that pictures the atom having a very small positively charged nucleus that carries almost all ot the mass of the atom surrounded by the very much smaller, negatively charged electrons

Question 3

nucleus of atom

Answer 3

the very small, but very dense, positively charged centre of an atom

Question 4

nucleon

Answer 4

a general term to describe protons and neutron

Question 5

nucleon number

Answer 5

the total number of neutrons and protons int he nucleus of an atom

Question 6

neutron number

Answer 6

the number of neutrons in the nucleus of an atom

Question 7

proton number

Answer 7

the number of protons in the nucleus of an atom

Question 8

nuclide

Answer 8

a specific combination of protons and neutrons in a nucleus

Question 9

unified atomic mass unit

Answer 9

one- twelfth of the mass of a carbon - 12 atoms

Question 10

isotopes

Answer 10

nuclei of the same element with different numbers of neutrons but the same number of protons

Question 11

ion

Answer 11

an atom that has lost or gained one or more electrons, so that is is electrically charges

Question 12

strong nuclear force

Answer 12

a fundamental force that acts between particles such as protons and neutrons, but which does not affect particles like electrons

Question 13

positron

Answer 13

the antiparticle of the electron; it has the same mass as the electron but has a charge +e

Question 14

β- decay

Answer 14

the emission of an electron as a neutron decays into a proton

Question 15

β+ decay

Answer 15

the emission of a positron as a proton decays into a neutron

Question 16

antimatter

Answer 16

material made up of antiparticles of the corresponding particles of ordinary matter

Question 17

electron volt

Answer 17

one electronvolt is the energy transferred when an electron travels through a potential difference of one volt

Question 18

electron neutrino

Answer 18

a particle that is given off with β+ decay with virtually no rest mass and no charge. Symbol v

Question 19

electron antineutrino

Answer 19

an antiparticle that iis given off with β- decay with virtually no rest mass and no charge. Symbol v bar

Question 20

leptons

Answer 20

subatomic particles that are not affected by the strong nuclear force and are believed to be fundamental

Question 21

hadrons

Answer 21

subatomic particles made up of quarks that are, therefore, affected by the strong nuclear force

Question 22

quarks

Answer 22

fundamental particles that make up hadrons

Question 23

baryon

Answer 23

a hadron made up from three quarks

Question 24

meson

Answer 24

a hadron made up of a quark and an antiquark