Term
| What nucleons make up the nucleus of an atom? |
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Definition
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Term
| How would you represent the nucleus of an atom? |
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Definition
Mass number (number of nucleons) on top and atomic number (number of protons) on the bottom with the element next to it 4 He 2 (not that great but you know what i mean) |
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Term
| What equation can be used to work out the number of neutrons in an atom? |
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Definition
Neutrons = neucleons - protons (N = A - Z) |
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Term
| Three types of nuclear reaction? |
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Definition
| Radioactive decay, nuclear fission and nuclear fusion |
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Term
Explain radioactive decay |
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Definition
| Unstable nucleus of an atom spontaneously changing into something different, emitting radiation as it does so. |
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Term
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Definition
| When a large nucleus splits into two smaller nuclei. Ccan be spontaneous or induced by bombarding with neutrons. |
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Term
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Definition
When two smaller nuclei join (fuse) to make one large nucleus. Can only occur when they have high energies (under high temperature) |
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Term
| What force keeps the nucleons in the nucleus, even though the Coulomb force of attraction is pulling them apart and Gravitational force is too weak? |
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Definition
| The Strong Force (hell yeah) |
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Term
| How can we find the radius of a nucleus? |
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Definition
Radius of nucleus = radius of one nucleon x number of nucleons to the power of 1/3 r = r0A1/3 |
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Term
| How can we find the density of a nucleus? |
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Definition
Density = mass volume So density of nucleus = mass 4/3∏r3 (yes that funny symbol IS pi) |
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Term
| How can we measure electrostatic (Coulomb) force? |
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Definition
F = 1 Q1Q2 4∏ε0 r2 ε0 = 8.85x10-12 Fm-1 |
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Term
| How can we measure gravitational force? |
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Definition
F = G m1m2 r2 G = 6.673x10-11 Nm2kg-2 |
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Term
What properties does the strong force have? (Thinking about the graph of distance between nucleon centres against strong force) |
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Definition
Short range force Acts between nucleons close together If nucleons overlap, becomes a repulsive force rather than an attractive force
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Term
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Definition
The difference between the potential energy of an atomic nucleus and the total potential energy of all its nucleons if they were seperate. Typically, potential energy of an atomic nucleus is lower than the potential energies of the seperate nucleons
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Term
| How can binding energy be a measure of stability? |
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Definition
The greater the binding energy per nucleon, the more stable the nucleus is |
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Term
| Which formula relates mass and energy and how does this affect nucleons? |
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Definition
ΔE = Δmc2 c = 2.998x108 ms-1 This means that the nucleons inside a nucleus have less mass than if they were seperate nucleons |
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Term
| So why does nuclear decay occur? |
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Definition
The nuclei want to become more stable Large nuclei have high binding energy, so split into smaller, more stable nuclei (nuclear fission) Small nuclei have low binding energy, so join together to a larger, more stable nucleus (nuclear fusion) Therefore the most stable nuclei are those of intermediate size (iron being the more stable of all)
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