Physics->ATOMIC STRUCTURE

• Why is nuclear fusion different from nuclear

  Fission?

  Greater amount of energy produced in nuclear fusion
• What is this mass deficit converted to?

  This mass deficit is converted into energy in the form of kinetic energy of the

  products and electromagnetic radiation.
• What is the mass of the nuclear fusion products heavier than?

  The mass of the heavier nucleus in a nuclear fusion reaction is lower than the total mass of the

  lighter nuclei.
• What happens in nuclear fusion?

  In nuclear fusion, two light nuclei join to create a larger, heavier nucleus releasing energy.
• What is the mass deficit converted to?

  This mass deficit is converted into energy in the form of kinetic energy of the products and electromagnetic radiation.
• What is the total mass of the products greater than ?

  The total mass of the products of a nuclear fission reaction is lower than the total mass of the

  reactants.
• What happens in nuclear fusion?

  In nuclear fission, a large unstable nucleus splits into two smaller nuclei (daughter nuclei)

  releasing neutrons and energy.
• What is an isotope ?

  Isotopes of an element are atoms with the same number of protons but different number of

  neutrons. Most elements have more than one isotope.
• What is the relative mass of a nucleus equal to ?

  The relative mass of a nucleus is equal to the nucleon number.
• What is the relative charge on a nucleus equal to ?

  The relative charge on a nucleus is equal to the proton number.
• How can the number protons and nucleons in a nucleotide be shown?

  The number of protons and nucleons in a nuclide can be shown using the nuclide notation, A

  X

  Z,

  where (X) is the element symbol.
• Nucleon number

  Nucleon/mass number (A) is the number of nucleons in the nucleus of an atom.
• Proton number

  Proton/atomic number (Z) is the number of protons in the nucleus of an atom.
• What are the relative charges of the particles ?

  The relative charges of protons, neutrons and electrons are +1, 0 and -1 respectively.
• What is the nucleus composed of?

  The nucleus is composed of protons and neutrons (together, we refer to them as nucleons).
• What happens if an atom gains electrons ?

  If an atom gains electrons, it becomes a negative ion.
• What happens is an atom loses electrons?

  If an atom loses electrons, it becomes a positive ion.
• Why is the charge of an atom neutral?

  There are always the same number of protons and electrons in an atom, so the overall

  charge is neutral.
• Rutherford and his team deduced that:

  • The atom has a very small nucleus surrounded mostly by empty space, as very

  few alpha particles hit or pass near a nucleus.

  • The nucleus is charged (likely positively), as

  the positively charged alpha particles experience

  a force in order to be scattered at large angles.

  • Most of the mass of the atom is concentrated

  in the nucleus, since the nucleus stays still when

  the alpha particles are deflected back.
• Rutherford and his team observed that:

  • Most of the alpha particles went

  straight through the gold foil.

  • A tiny amount of alpha particles were

  scattered at large angles.

  • A few alpha particles were deflected

  back the way they came.
• What are atoms composed of ?

  Atoms are composed of a positively charged nucleus orbited by negatively charged electrons.