Open In App

Rutherford’s Alpha Scattering Experiment

Last Updated : 06 Mar, 2024
Like Article

Rutherford’s Alpha Scattering Experiment is the fundamental experiment done by Earnest Rutherford’s Alpha Scattering Experiment that gives the fundamental about the structure of the atom. Rutherford in his experiment directed high-energy streams of α-particles from a radioactive source at a thin sheet (100 nm thickness) of gold. Then the deflection of these alpha particles tells us about the structure of atoms.

In this article, we will study about constituents of atoms, Rutherford’s  Alpha Scattering Experiment,

What are Constituents of an Atom?

An atom consists of Electrons, Protons, and Neutrons are the fundamental particles or sub-atomic particles that build the structure of an atom. Let us understand each term.

  • Electron: In 1897, J. J. Thomson discovered negatively charged particles towards the anode, these rays are emitted by the cathode in a cathode ray experiment. Then these negatively charged particles are proposed as Electrons.
  • Protons: In 1886, Ernest Goldstein discovered that an anode emitted positively charged particles with a different condition in the same tube,  known as Canal rays or as Protons.
  • Neutrons: A subatomic particle with no charge and a mass equivalent to protons in the nucleus of all atoms was discovered by J. Chadwick. These neutrally charged particles are termed Neutrons.

The image added below shows the structure of an atom.

Learn more about, Atomic Structure


Structure of Atom

Isotopes are the elements that have the same atomic number but different mass. e.g. Isotopes of the Hydrogen atoms are Protium (1H1), Deuterium (2H1) and Tritium(3H1). Isotopes of the Carbon atoms are 12C6, 13C6, 14C6.

Isobars are the elements that have different atomic number but have same mass number. e.g. 19K40, 18Ar40, 20Ca40, here all the elements having same mass number hence they are isobars.

Rutherford’s Alpha Scattering Experiment

He conduct an experiment by bombarding alpha particles into a thin sheet of gold and then notices their interaction with the gold foil and trajectory or path followed by these particles.

Rutherford's Alpha Scattering Experiment

In the experiment, Rutherford passes very high streams of alpha-particles from a radioactive source i.e. alpha-particle emitter, at a thin sheet of100 nm thickness of gold. In order to examine the deflection produced by the alpha particles, he placed a screen of fluorescent zinc sulphide around the thin gold foil. Rutherford made certain observations that oppose Thomson’s atomic model.

Observations of Rutherford’s Alpha Scattering Experiment

The observations of Rutherford’s Alpha Scattering Experiment are:

  • First, he observe that most of the α-particles that are bombarded towards the gold sheet pass away the foil without any deflection, and hence it shows most of the space is empty.
  • Out of all, some of the α-particles were deflected through the gold sheet by very small angles, and hence it shows the positive charge in an atom is non-uniformly distributed. The positive charge is concentrated in a very small volume in an atom.
  • Very few of the alpha-particles(1-2%) were deflected back, i.e. only a very less amount of α-particles had nearly 180° angle of deflection. this shows that the volume occupied by the positively charged particles is very small as compared to the total volume of an atom.

Rutherford Atomic Model

Rutherford proposed the atomic structure of elements, on the basis of his experiment. According to Rutherford’s atomic model:

  • Positively charged particle was concentrated in an extremely small volume and most of the mass of an atom was also in that volume. He called this a nucleus of an atom.
  • Rutherford proposed that there is negatively charged electrons around the nucleus of an atom. the electron surrounding the nucleus revolves around it in a circular path with very high speed. He named orbits to these circular paths.
  • Nucleus being a densely concentrated mass of positively charged particles and electrons being negatively charged are held together by a strong force of attraction called electrostatic forces of attraction.
Rutherford-Atomic Model

Rutherford Atomic Model

Learn about, Rutherford Atomic Model

Limitations of Rutherford Atomic Model

The Rutherford atomic model is failed to explain certain things.

  • According to Maxwell, an electron revolving around the nucleus should emit electromagnetic radiation due to accelerated charged particles emit electromagnetic radiation. but Rutherford model says that the electrons revolve around the nucleus in fixed paths called orbits. The radiation would carry energy from the motion which led to the shrinking of orbit. Ultimately electrons would collapse inside the nucleus.
  • As per the Rutherford model, calculations have shown that an electron would collapse in the nucleus in less than 10-8 seconds. So Rutherford model has created a high contradiction with Maxwell’s theory and Rutherford later could not explain the stability of an atom.
  • Rutherford also did not describe the arrangement of electrons in the orbit as one of the other drawbacks of his model.

Regardless of seeing the early atomic models were inaccurate and failed to explain certain experimental results, they were the base for future developments in the world of quantum mechanics.

Sample Questions on Rutherford’s Alpha Scattering Experiment

Some sample questions on Rutherford’s Alpha Scattering Experiment is,

Q1: Represent Element ‘X’ which contains 15 electrons and 16 neutrons.


Atomic number of element = No. of electron = 15

Mass number of element = no. of electrons + no. of neutrons = 15 + 16 = 31

Correct representation of element X is 31X15.

Q2: Name particle and give its location in the atom which has no charge and has a mass nearly equal to that of a proton.


The particle which has no charge and has a mass nearly equal to that of a proton is a neutron and it is present in the nucleus of the atom.

Q3: An atom has both electron attribute negative charge and protons attribute positive charge but why there is no charge?


Positive and negative charges of protons and electrons are equal in magnitude, they cancel the effect of each other. So, the atom as a whole is electrically neutral.

Q4: What is Valency of Sodium Atom (Na)?

The atomic number of sodium = 11. Electronic configuration (2, 8, 1). By losing one electron it gains stability hence its valency is 1.

Q5: Which property do the following pairs show? 209X84 and 210X84

Atomic number of X is the same hence the pair shows an isotopic property. So, 209X84 and 210X84 are isotopes.

Read More,

Rutherford’s Alpha Scattering Experiment FAQs

What is Name of Atom which has one electron, one proton and no neutron?

Atom with one electron, one proton and no neutron is Hydrogen, (1H1).

What is Ground State of an Atom?

It is the state of an atom where all the electrons in the atom are in their lowest energy state or levels is called the ground state.

What was Rutherford’s Alpha Particle Scattering Experiment?

Rutherford’s Alpha Particle Scattering Experiment is the fundamental experiment that gives the basic structure of an atom.

What was Conclusion of Rutherford’s Alpha Scattering Experiment?

Conclusion of Rutherford’s Alpha Scattering Experiment is, Atom is largely empty and has a heavy positive-charged body at the center called the nucleus. The central nucleus is positively charged and the negatively-charged electrons revolve around the nucleus.

Previous Article
Next Article

Similar Reads

Alpha Particle Scattering and Rutherford's Nuclear Model of Atom
In today's universe, the smallest particle of matter is an atom. It is the smallest possible result obtained by dividing the matter without releasing electrically charged particles. It was first proposed by John Dalton in the name of the Atomic Theory. This theory has its own evolution given by different scientists like J.J Thompson, Ernest Rutherf
8 min read
Size of The Nucleus - Rutherford Gold Foil Experiment
Physics requires an understanding of matter's underlying structure. Without the Rutherford gold foil experiment, it would be impossible to determine the size of the nucleus, which is the subject of this article. The Rutherford atom model was the first proper interpretation of the atom, and it served as the foundation for Bohr's interpretation. Ruth
7 min read
Polarisation by Scattering and Reflection
Physical optics, frequently known as wave optics, is a discipline of optics that looks at obstruction, diffraction, polarization, and different peculiarities for which the mathematical optics beam estimate isn't material. The connection between waves and light beams is very much portrayed by wave optics. Light is a sort of energy that moves through
11 min read
Scattering of Light and Tyndall Effect
Tyndall effect, also known as the Tyndall phenomenon, is the scattering of a light beam by a medium containing tiny suspended particles—for example, smoke or dust in a room—which makes a light beam entering a window visible. Short-wavelength blue light is dispersed more strongly than long-wavelength red light, similar to Rayleigh scattering. Let's
9 min read
Scattering of Light
Scattering of Light is a fascinating phenomenon that occurs when light travel through different mediums and is scattered by the particles of the medium or other irregularities. Light is nothing but energy which can be either considered waves or particles (dual nature of light) and travels in a straight line and as light reaches our eyes then we can
11 min read
Rutherford Atomic Model
Rutherford Atomic Model was proposed by Ernest Rutherford in 1911. It is also called the Planetary Model of the Atom. It introduced the concept of a dense, positively charged nucleus at the center of an atom, with electrons orbiting around it, forming the basis for modern atomic theory. In this article, we will learn about Rutherford's Alpha Scatte
6 min read
Drawbacks of Rutherford's Atomic Model
In Rutherford's Model of the Atom, Rutherford performed an experiment based on that experiment some of the hypotheses are given. At that time those hypotheses are considered revolutionary as there was an experiment to back that hypothesis. But as the experiment performed by Rutherford is rudimentary in nature, this model of the atom can be seen wit
10 min read
Young's Double Slit Experiment
Optics is the part of material science that concentrates on the conduct and properties of light, incorporating its connections with issues and the development of instruments that utilise or recognize it. Optics as a rule depicts the conduct of apparent, bright, and infrared light. Since light is an electromagnetic wave, different types of electroma
11 min read
Incomplete Dominance & Mendel's Experiment
Incomplete Dominance is a form of intermediate inheritance where neither of the two alleles for a particular trait is completely dominant over the other. In this type of dominance, the heterozygous phenotype is a blend or intermediate between the two homozygous phenotypes. The concept of incomplete dominance emerged as a significant discovery follo
6 min read
Cathode Ray Experiment
Cathode Ray Experiment, also known as the Crookes tube experiment, is a historically significant experiment in the field of physics that helped scientists understand the nature of electrons. English scientist Sir J.J. Thomson performed an experiment using a Cathode Ray Tube, which led to the discovery of an electron. In this article, we will discus
7 min read