By the end of this presentation, you should be able to: Select and use Coulomb’s law to determine the force of repulsion, and Newton’s law of gravitation.

Slides:



Advertisements
Similar presentations
Radioactive Decay. - Alpha Decay The emission of an particle from the nucleus of an atom is called alpha decay An alpha particle is just a helium nucleus.
Advertisements

5.3.2 Fundamental Particles
Nuclear Physics. Outcomes What is the difference between alpha, beta and gamma radiation? What are the rules for writing equations of nuclear reactions?
AP Physics V.B Nuclear Physics Nuclear Structure.
The Atom - Continued. What are quarks? protons & neutrons can be separated into smaller particles called quarks these are a different kind of particle.
20th Century Discoveries
Fundamental Forces of the Universe
Chapter 29 Nuclear Physics.
Board Work 1.What is the electrical interaction between a.a proton and another proton in a nucleus? b.a proton and a neutron in a nucleus? c.a neutron.
The Atomic Nucleus and Radioactivity The nucleus is composed of particles called nucleons, which are protons and neutrons. The number of nucleons is called.
Chapter 30 Nuclear Physics
These notes were typed in association with Physics for use with the IB Diploma Programme by Michael Dickinson For further reading and explanation see:
4 Basic Forces of Nature strong force = very strong, but very short-ranged. It acts only over ranges of order centimeters and is responsible for.
5.3.1 The Nuclear Atom.
Atomic Theory, Isotopes and Radioactive Decay
5.3.2 Fundamental Particles. (a) explain that since protons and neutrons contain charged constituents called quarks they are, therefore, not fundamental.
Alpha Beta Gamma. Lesson Contents 1.Physical properties of ,  and  2.Penetrating power of ,  and  3.N v Z  graphs 4.Decay laws.
Learning Targets I can name the force that holds the atom’s nucleus together I can describe the two reasons why some isotopes are radioactive. I can describe.
Modern Physics Radioactive Decay. Look at the periodic table given to you. Find element with the atomic number 6 What is it?
Ch. 1 Fun with the Periodic Table
PHYS 221 Recitation Kevin Ralphs Week 14. Overview Nuclear Physics – Structure of the Nucleus – Nuclear Reactions.
Nuclear Chemistry. Two main forces in nucleus  Strong nuclear force—all nuclear particles attract each other  Electric forces—protons repulse each other.
NUCLEAR CHEMISTRY QUIZ.
Subatomic Physics Chapter Properties of the Nucleus The nucleus is the small, dense core of an atom. Atoms that have the same atomic number but.
In the late years of the 19th century scientists were interested in experiments about the rays that certain elements were emitting. After various experiments.
Changes in the Nucleus Objectives: 1. Describe the changes that accompany nuclear reactions. 2. Define radioactivity. Key Terms: nuclear reaction, strong.
Lecture 1 & 2 © 2015 Calculate the mass defect and the binding energy per nucleon for a particular isotope.Calculate the mass defect and the binding.
Alpha Beta Gamma.
S-145 What is the difference between the terms radioactive and radiation?
The nucleus consists of protons and neutrons, collectively called nucleons. The number of protons is the atomic number. Protons plus neutrons is the atomic.
Aim: How can we explain the four fundamental forces and the standard model? Do Now: List all the subatomic particles that you can think of.
Particles and how they interact
3-4 Changes in the Nucleus
The Nucleus Nucleons- the particles inside the nucleus: protons & neutrons Total charge of the nucleus: the # of protons (z) times the elementary charge.
Nuclear Radiation 9.2. The Nucleus Protons and neutrons Charge of electrons and protons – x C = e –Proton +e –Electron -e.
Unstable Nuclei & Radioactive Decay Radioactivity Nucleus of an element spontaneously emits subatomic particles & electromagnetic waves. Nucleus of an.
Topic 7.2 The ABC’s of Radioactivity
Radioactive Decay The nuclei of some chemical elements are unstable against the strong nuclear force holding them together, resulting in a spontaneous.
Fundamental Forces in Nature
Nuclear Chemistry. Chemical ReactionsNuclear Reactions - Occur when bonds are broken or formed -Occur when the nucleus emits particles or rays -Atoms.
Nuclear Transformations Objectives: 1. What determines the type of decay a radioisotope undergoes? 2. How much of a sample of a radioisotope remains after.
Nuclear Radiation Half-Life. What is Radiation? Penetrating rays and particles emitted by a radioactive source Result of a nuclear reaction! –Involves.
What is going on in there?
Nuclear Physics and Radioactivity AP Physics Chapter 30.
Stable and Unstable Nuclei
Fundamental Forces. Gravitational force - an attractive force that exists between all objects. The gravitational force between the center of the Earth.
1 This is Jeopardy Nuclear Chemistry 2 Category No. 1 Category No. 2 Category No. 3 Category No. 4 Category No Final Jeopardy.
Nuclear Physics. Nuclear Structure Nucleus – consists of nucleons (neutrons and protons) Nucleus – consists of nucleons (neutrons and protons) Atomic.
Radioactivity By the end of this chapter you should be able to: describe the properties of alpha, beta and gamma radiations; explain why some nuclei are.
Chapter 14 Section 14.1.
Nuclear, i.e. pertaining to the nucleus. Nucleus Most nuclei contain p + and n 0 When packed closely together, there are strong attractive forces (nuclear.
Section 2: Radioactive Decay
By the end of this presentation you should be able to…… List the three types of nuclear radiation Describe the nature of each type.
II. The Nucleus of the Atom. What makes up the nucleus of an atom? A. Compostion (Nucleons) 1. Protons a. Mass universal mass units b. Indicated.
Radioactive Decay When elements have unstable nuclei, they decay, forming more stable nuclei and giving off energy. In this lesson, you will learn what.
2.3.2 the strong nuclear force
The Atomic Nucleus.
The Strong Nuclear Force
Fundamental Forces of the Universe
Rutherford’s α scattering experiment
Fundamental Forces of the Universe
Nuclear Chemistry.
FAMILIAR FORCES Probably the most familiar force is the gravitational force. It does not only pull objects towards the centre of the Earth. The Earth is.
Physics I Gravity.
Certain elements radiate particles and turn into other elements.
Atomic Physics Uses of radiation.
Fundamental Forces.
31.1 Structure and Properties of the Nucleus
The nucleus of an atom contains two particles:
Presentation transcript:

By the end of this presentation, you should be able to: Select and use Coulomb’s law to determine the force of repulsion, and Newton’s law of gravitation to determine the force of attraction, between two protons at nuclear separations and hence the need for a short- range, attractive force between nucleons. Describe how the strong nuclear force between nucleons is attractive and very short-ranged. Use nuclear decay equations to represent simple nuclear reactions. State the quantities conserved in a nuclear decay. Estimate the density of nuclear matter.

 Consider a helium nucleus (which has two protons in it)  Calculate the force of repulsion between them ◦ Use Coulomb’s Law and r = 1.6 x m (two proton radii)

 Calculate the force of attraction due to their masses. You want to see if this force is sufficient to overcome the repulsion an keep the constituents of the nucleus from flying apart ◦ Use Newton’s Law of Gravitation and r=1.6 x m (two proton radii)

 The electrostatic repulsion >> the gravitational attraction.  F E / F G = 90 / 7.3 x =  There must be another force that is attractive, acts at this small separation, and is very strong

1.It is the strongest of all four forces 2.It acts over a very short distance 3.If an attempt is made to push nucleons closer, the force will become repulsive 4.If you increase the separation, the force rapidly drops to zero. i.e. is has no influence outside of the nucleus

 Small nucleus  nuclear force acts over small distance  all nucleons affected and kept together  nucleus is stable: N = Z  Large nucleus  strong nuclear force cannot act to influence all nucleons  protons cannot be too close together or they will fly apart  more neutrons (than protons) will force the protons to be further apart  repulsive electrostatic force is smaller: N > Z  Nuclei with 83 protons experience such a large electrostatic repulsion that they are unstable. This results in radioactivity

ALPHA DECAY: The nucleus emits a particle which consists of 2 protons and 2 neutrons. Alpha decay of plutonium-240 into uranium-236 and an alpha particle

BETA DECAY: There are 2 types of beta decay  beta-plus ( b + ) decay eta–minus ( b - ) decay tthe “weak interaction” between “quarks” is responsible for beta decay Beta-minus decay: a neutron in the nucleus decays into a proton (stays in the nucleus) and an electron and an electron antineutrino. The electron is detected as the beta particle. Beta-plus decay: a proton in the nucleus decays into a neutron (stays in the nucleus) and an electron and an electron neutrino. The electron is detected as the beta particle.

1. Calculate the density of a proton considering: 2. Neutrons have a similar mass and volume to protons, therefore a similar density. 3. Since nuclei are made up of protons and neutrons in close proximity, then this must be similar to the density of the any nucleus.