p6.1 knowledge gaps

Question 1

how are electrons arranged in atoms

Answer 1

in energy levels around the nucleus
lowest energy level is closest to the nucleus

Question 2

what happens when atoms absorb em radiation (photon model)

Answer 2

in photon model em radiation is emitted and absorbed in packets of energy called photons

energy of photons is proportional to frequency

photon of the right energy will excite an electron to a higher energy level

if photon has enough energy the electron cane be removed which causes the atom to become ionised

Question 3

changes in atoms and nuclei can…

Answer 3

also generate and absorb radiations over à wide frequency range

Question 4

define half life

Answer 4

the time it takes for undecayed or radioactive nuclei to halve

Question 5

how do alternators generate alternating current

Answer 5

have two commutators
first wire always connected to one commutator, second wire always connected to other commutator
as magnetic field is being cut the p.d is max
from upwards to downwards (or downwards to upwards) the coil moves in opposite direction which produces a negative p.d (from positive) and à current that is AC