The dense centre of an atom that contains the protons and neutrons
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100
What is the mass of an proton compared to an electron?
1800 X the mass
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100
Name the three kinds of radioactive Decay
Alpha decay, Beta decay, and gamma decay
100
What is Half-Life?
The average length of time for half of the parent nuclei in a sample to decay.
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100
Americium-241 goes through alpha decay.
241 Am ---> 237 Np + 4 He
95 93 2
200
What is a proton?
A positively charged particle that's positioned within the nucleus of an atom. Has a charge of +1
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200
What does the atomic number tell you about a certain element?
It tells you how many protons it ha$
200
What is the mass of an Alpha particle compared to an electron?
7000 $
200
How can we determine WHEN an individual nucleus will decay?
you cant ha
200
Cesium-137 goes through Beta decay
137 Cs --> 137 Ba + 0 e
55 56 -1
300
What is an Isotope?
Atoms that have different mass numbers. Has the same number of protons but different numbers of neutrons
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300
Name the three isotopes of Hydrogen
hydrogen, deuterium,. and tritium
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300
What is the slowest moving method of decay?
Alpha decay
300
Over time during half lives, what will decrease?
The parent nuclei will decrease, so will the RATE of the decay
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300
Boron-12 goes though gamma decay (beta decay)
12B --> 12C* + 0 e
5 6 +1
12C* ---> 12 C + 0 y
6 6 0
400
What is Radioactive Decay?
When an unstable nucleus emits radiation in the form of an alpha particle, a beta particle, or gamma ray.
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400
What are the differences between different isotopes of the same element?
They can have a variety of physical properties. Different numbers of neutrons
400
What stops an X-ray from penetrating?
thin lead
$$
400
What does the activity of a sample while going through half lives depend on?
It depends on the size of the sample, and the age of the sample
$$$
400
Radium-226 has a half-life of 1600 years. it has the activity of 500 MBq. What is the activity level after 8000 years?
15.625 Mbq
500
What is a decay series?
When an parent nucleus produces a daughter nucleus that is also unstable. The process keeps happening and repeating until the daughter nucleus is stable
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
500
Who discovered neutrons?
JAMES CHADWICK.
500
Where does the electron come from in beta decay?
It comes from the decay of a neutron
500
On a half life graph, what does the y and x axis represent?
The activity level and the time$$$
500
How much of a 100 g sample of 198Au is left after 8.10 days if its half life is 2.7 days?