# Why did Thomson place his negative particle into a positive sphere?

## Why did Thomson place his negative particle into a positive sphere?

The plum pudding model Thomson knew that atoms had an overall neutral charge. Therefore, he reasoned that there must be a source of positive charge within the atom to counterbalance the negative charge on the electrons.

## What was JJ Thomson’s model of the atom called?

the plum pudding model
Popularly known as the plum pudding model, it had to be abandoned (1911) on both theoretical and experimental grounds in favour of the Rutherford atomic model, in which the electrons describe orbits about a tiny positive nucleus.

What is the positive pole in JJ Thomson’s experiment called?

anode
An electric current was passed from the cathode (the negative pole) to the anode (positive pole). Several experiments showed that particles were emitted at the cathode and that these particles had a negative charge. These experiments demonstrated the presence of electrons. Figure 1.

What did JJ Thomson discover about matter?

Discovery of the electron. Thomson’s most important line of work, interrupted only for lectures at Princeton University in 1896, was that which led him in 1897 to the conclusion that all matter, whatever its source, contains particles of the same kind that are much less massive than the atoms of which they form a part.

### Where did Thomson think the positive charge was in the atom?

In Thomson’s plum pudding model of the atom, the electrons were embedded in a uniform sphere of positive charge like blueberries stuck into a muffin. The positive matter was thought to be jelly- like or a thick soup. The electrons were somewhat mobile.

### What did Thomson believe about the atom?

In 1903, Thomson proposed a model of the atom consisting of positive and negative charges, present in equal amounts so that an atom would be electrically neutral. He proposed the atom was a sphere, but the positive and negative charges were embedded within it.

How did JJ Thomson describe the atom?

In Thomson’s model, the atom is composed of electrons surrounded by a soup of positive charge to balance the electrons’ negative charges, like negatively charged “plums” surrounded by positively charged “pudding”.

Did Rutherford theorized that atoms contain a positively charged region called the nucleus?

Rutherford disproves the plum pudding model of the atom. Rutherford theorized that atoms contain a positively charged region called the nucleus. He carried out experiments that measured the scattering of alpha particles by heavy atoms.

#### What are 5 facts about JJ Thomson?

J. J. Thomson

• Beginnings: School and University.
• Early Research Work.
• Discovery of the Electron – The first subatomic particle.
• The Atom as a Plum Pudding.
• Invention of the Mass Spectrometer.
• Every Hydrogen Atom has only one Electron.
• Discovery of Isotopes of Stable Elements.
• Some Personal Details and the End.