Topic 5.1 - The Nuclear Atom Flashcards Preview

Physics > Topic 5.1 - The Nuclear Atom > Flashcards

Flashcards in Topic 5.1 - The Nuclear Atom Deck (12)
Loading flashcards...
1

Describe the structure of a nucleus.

The nucleus is positively charged and is made of protons (positive) and neutrons (neutral).

2

What are the relative charges of protons, electrons and neutrons?

  • Protons: +1
  • Electrons: -1 
  • Neutrons: 0 

3

What are the relative masses of protons, electrons and neutrons?

  • Protons: 1
  • Electrons: 0 (0.0005
  • Neutrons: 1

4

What are the conclusions of Rutherford’s experiment?

  • Most of an atom is empty space
  • The nucleus has a positive charge  
  • Most of the mass is concentrated in the nucleus

5

Describe Rutherford's atomic model 

There is a positive nucleus at the centre of an atom, with negative electrons existing in a 'cloud'/region around the nucleus 

6

What is an isotope?

Atoms that are the same element with the same number of protons. However they have a different number of neutrons so therefore different masses.

7

What do all atoms of the same element share?

The same number of protons (atomic number).

8

What is nuclear fission?

When a large and unstable nucleus splits to form two smaller nuclei, neutrons and energy.

9

What is nuclear fusion?

When two small nuclei fuse to form a heavier nucleus and release energy.

10

What does Z represent?

The atomic (proton) number; the number of protons in the nucleus of an atom 

11

What does A represent?

  • The nucleon number; the numbers of protons and neutrons in the nucleus of an atom.
  • This is also known as the atom’s mass.

12

Describe Rutherford's experiment 

  • Alpha particles (charge +2) were fired at a thin
    sheet of gold foil
  •  Most particles went straight through
  •  Some particles were deflected by small angles
    (< 90o)
  •  A few particles were deflected by large angles
    (> 90o)