Question

question 3
which of the following discoveries is j. j. thompson, an english physicist, credited for determining?
the discovery of the electron, a subatomic negatively charged particle, and its mass - to - charge ratio.
he made groundbreaking contributions to quantum theory by suggesting that all matter has both wave and particle properties.
one of the first to develop the modern atomic theory describing the chemical and physical properties of elements and molecules.
he described and quantified the observation that many metals emit electrons when light shines upon them termed the photoelectric effect.
using charged oil drops, he was able to measure the elementary electronic charge of a single electron.

Explanation:

J. J. Thompson is known for the discovery of the electron, a subatomic negatively - charged particle, and for determining its mass - to - charge ratio. The other options describe contributions of different scientists. For example, the idea of matter having both wave and particle properties is associated with de Broglie, modern atomic theory with Dalton, the photoelectric effect with Einstein, and measuring the elementary electronic charge with Millikan.

Answer:

The discovery of the electron, a subatomic negatively charged particle, and its mass - to - charge ratio.