Nuclear chemistry...................pptx

Nuclear chemistry...

1. NUCLEAR CHEMISTRY Introduction to JASTINE T. BERMUNDO 12-STEM FARADAY

2. 04 GRAVITATIONAL FORCE The most familiar force is gravity. It is responsible for keeping our feet on the ground and holding Earth in its orbit around the Sun. 4 03 ELECTROMAGNETIC FORCE It holds two objects with opposite electrical charges like proton and electron that make up one hydrogen atom . 3 02 WEAK NUCLEAR FORCE The weak force is responsible for interactions between subatomic particles – the tiny particles that are the building blocks for matter, like protons, neutrons, and electrons.. 2 01 STRONG NUCLEAR FORCE It holds together the building blocks of atoms. It always attracts and works at two different size scales in atoms. At the level of an atomic nucleus, the strong force holds together the protons and neutrons that form the essence of the elements 1 THE 4 FUNDAMENTAL FORCES OF THE UNIVERSE

3. 04 GRAVITATIONAL FORCE The most familiar force is gravity. It is responsible for keeping our feet on the ground and holding Earth in its orbit around the Sun. 4 THE 4 FUNDAMENTAL FORCES OF THE UNIVERSE 03 ELECTROMAGNETIC FORCE It holds two objects with opposite electrical charges like proton and electron that make up one hydrogen atom . 3 02 WEAK NUCLEAR FORCE The weak force is responsible for interactions between subatomic particles – the tiny particles that are the building blocks for matter, like protons, neutrons, and electrons.. 2 01 STRONG NUCLEAR FORCE It holds together the building blocks of atoms. It always attracts and works at two different size scales in atoms. At the level of an atomic nucleus, the strong force holds together the protons and neutrons that form the essence of the elements 1

4. 01 03 02 How do forces work in a large nucleus?

5. 01 03 02 How do forces work in a large nucleus? In a large nucleus, the strong force holds together only the particles that are closest to one another.

6. 03 How do forces work in a large nucleus? In a nucleus with many protons, the electric force repels protons that are far apart. 01 02

7. How do forces work in a large nucleus? In a nucleus with many protons, the electric force repels protons that are far apart. 03 02

8. Radioactivity • When the strong force can hold a nucleus together forever, the nucleus is stable. • If not, the nucleus becomes unstable and can break apart or decay by emitting particles and energy. • Large nuclei are more unstable; all with more than 83 protons are radioactive.

9. What makes nuclei unstable? The ratio of neutrons to protons determines whether a nucleus is stable or unstable. • Small isotopes 1 neutron:1 proton • Large isotope 3 neutrons: 2 protons • Generally, nuclei with too many or too few neutrons compared to the numbers are unstable or radioactive

10. 1. Henri Becquerel accidentally left pieces of uranium salt in a drawer on a photographic plate. 2. Marie Sklodowska - Marie Curie was the first woman to win a Nobel Prize, in Physics, and with her later win, in Chemistry, she became the first person to claim Nobel honors twice. Her efforts with her husband Pierre led to the discovery of polonium and radium, and she championed the development of X-rays. 3. Pierre Curie- was a brilliant French physicist who co-discovered  radium and polonium  with his wife Marie Curie, earning them the Nobel Prize in Physics in 1903. Who discovered Radioactivity?

11. Nuclear Reactions NUCLEAR EQUATIONS • A balanced chemical reaction equation reflects the fact that during a chemical reaction, bonds break and form, and atoms are rearranged, but the total numbers of atoms of each element are conserved and do not change. • A balanced nuclear reaction equation indicates that there is a rearrangement during a nuclear reaction, but subatomic particles are rearranged rather than atoms.

12. 2 Kinds of Nuclear Reaction 1. Nuclear Decay • also called radioactive decay, an unstable nucleus emits radiation and is transformed into the nucleus of one or more other elements. • The resulting daughter nuclei have a lower mass and are lower in energy (more stable) than the parent nucleus that decayed . 2. Nuclear Transmutation • a nucleus reacts with a subatomic particle or another nucleus to form a product nucleus that is more massive than the starting material.

13. NUCLEAR DECAY 1. ALPHA DECAY- Many nuclei with mass numbers greater than 200 undergo alpha (α) decay 2. BETA DECAY • Nuclei that contain too many neutrons often undergo beta (β) decay • in which a neutron is converted to a proton and a high-energy electron that is ejected from the nucleus as a β particle 3. POSITRON EMISSION • is the opposite of beta decay. • neutron-poor nuclei, which decay by transforming a proton to a neutron and emitting a high-energy positron 4. ELECTRON CAPTURE • Another way for neutron-poor nuclei to gain a neutron is which an electron in an inner shell reacts with a proton to produce a neutron • When a second electron moves from an outer shell to take the place of the lower-energy electron, an X-ray is emitted. 5. GAMMA EMISSION • Many nuclear decay reactions produce daughter nuclei that are in a nuclear-excited state. • a nucleus in an excited state releases energy in the form of a photon when it returns to the ground state.