topic 6 Flashcards
figure 4 shows geiger muller tube for measuring radioactivity.
describe how a teacher should use a geiger muller tube to compare the count rates from two different radioactive rocks
put rocks in front of tube and measure the count rate separately for each rock. measure each count for the same time period and repeat the readings and take an average
complete the following nuclear equation:
99 ? 0
Mo —> Tc + B
42 ? -1
99 99 0
Mo —> Tc + B
42 43 -1
explain why a high temperature is needed for a fusion reaction
high temperature means high energy is needed to overcome the force of repulsion between nuclei because they have the same charge
explain how the graphite core and movable rods are used to maintain and control the chain reaction (6)
neutrons are released in a chain reaction. slower neutrons are needed for a chain reaction however some are too fast. to help this control rods can be moved in ad out to control the speed of the reaction. the graphite core is the moderator and this slows down the neutrons. the moveable rods absorb the neutrons and make more or fewer neutrons available for fission
carbon 13 and carbon 14 are isotopes of carbon.
13 14
C and C
6 6
complete the info for an atom of carbon 13 and an atom of carbon 14
CARBON 13:
number of neutrons in nucleus - 7
number of electrons in orbit around nucleus - 8
CARBON 14:
number of neutrons in nucleus - 6
number of electrons in orbit around nucleus - 6
state the name of an instrument that can be used to measure radioactivity
geiger muller counter
state two sources of background radiation
cosmic rays
the sun
radioactive substances are used in the generation of electricity
state two other uses of radioactive substances
smoke alarm
sterilising
figure 1 diagram of a nuclear reactor used to generate electricity
state the name of the parts labelled p and q
p - control rods
q - moderator
explain how neutrons enable a nuclear chain reaction to take place
a neutron collides with a nucleus
which of these describes the isotopes of an element
A) same atomic number, different neutrons
B) same atomic number, different protons
C) same mass number, different neutrons
D) same mass number, different protons
A) same atomic number, different neutrons
which decay is shown in figure 9?
A) alpha
B) beta minus
C) beta plus
D) gamma
C) beta plus
the global demand for electricity is increasing.
discuss the arguments for and against using nuclear power to meet the demand for electricity
firstly, we are running out of fossil fuels so nuclear can replace where we have previously used fossil fuels. as well as this there are no CO2 emissions so it doesnt contribute to climate change. it is also low cost so better for the economy than other more expensive alternatives. secondly, on the other hand it is more expensive to set up. it also creates radioactive waste which could contaminate an area and this waste also lasts a long time which could cause storage issues
GM tube connected to a counter. teacher places the GM tube near to a radioactive source. a student starts the counter and clock at the same time and writes down the readings shown on the counter every 15s.
student says the experiment must have been done carelessly because the data seemed quite scattered away from the line of best fit. the teacher claims such results should be expected in radioactivity experiments. justify this claim
the process of radioactivity decay is unpredictable so the count rate wouldn’t be constant
