Unlocking the Secrets of Electron Charge

Who is credited with developing the first atomic model?

John Dalton

What did Democritus call the smallest pieces of matter?

atomos

What is the purpose of atomic theory?

To understand what matter is and how it behaves

Who discovered electrons using a cathode ray tube?

J. J. Thomson Signup and view all the answers

What is the name of the model of the atom developed by Erwin Schrodinger?

Quantum model or electron cloud model Signup and view all the answers

What did John Dalton's atomic model state?

Matter is made up of tiny particles called atoms that cannot be divided into smaller pieces and cannot be destroyed Signup and view all the answers

Who were the main scientists involved in early atomic theory?

Democritus, John Dalton, J. J. Thomson, Ernest Rutherford, Niels Bohr, Robert Millikan, Irwin Schrodinger Signup and view all the answers

What was Dalton's atomic theory?

Atoms are the smallest pieces of matter and contain no smaller parts. All atoms in an element have identical atoms, different elements have different atoms, and atoms of different elements can combine to make compounds. Signup and view all the answers

What were the two main types of atomic models developed in the early atomic theory?

Solid spheres or semi-solid spheres with smaller particles evenly distributed throughout; dense nucleus with electrons orbiting the nucleus Signup and view all the answers

Who disproved Aristotle's belief that matter could be divided infinitely without changing its properties?

John Dalton Signup and view all the answers

What did Ernest Rutherford conclude about the atom after his gold foil experiment?

The atom consists mostly of empty space and that all the positive charge is not evenly spread throughout the atom but instead squished into a teeny tiny nucleus in the center of the atom. Signup and view all the answers

How did Robert Millikan determine the charge of an electron?

He used his 'oil drop experiment,' where he sprayed charged oil drops between two metal plates and balanced out the downward gravitational force with electrical force equal to the charge on the oil drop, which caused the oil drop to repel upward. Signup and view all the answers

Who is credited with discovering the electron?

J. J. Thomson Signup and view all the answers

What was J. J. Thomson's model of the atom called?

the 'plum pudding' model Signup and view all the answers

What did Ernest Rutherford's experiment with gold foil and alpha particles reveal about the atom?

the atom consists mostly of empty space and has a small, dense, positively charged nucleus Signup and view all the answers

How did Robert Millikan determine the charge of an electron?

using his 'oil drop experiment' Signup and view all the answers

What did Dalton's model of the atom state about the composition of matter?

that matter is made up of tiny particles called atoms that cannot be divided into smaller pieces and cannot be destroyed Signup and view all the answers

What were Dalton's findings about atoms and gasses?

Dalton's findings supported the theory that gasses are matter made of tiny, round particles (atoms), and that different gasses were made of different types of atoms. His experiments showed that atoms do exist and that all atoms in pure elements are identical to each other. Signup and view all the answers

How did J.J. Thomson's findings challenge Dalton's model of the atom?

Thomson's findings showed that Dalton's model of the atom as a solid sphere without smaller parts was incorrect. Thomson discovered the existence of electrons, which are tiny, negatively-charged particles within atoms. Signup and view all the answers

What did Rutherford's gold foil experiments reveal about atomic structure?

Rutherford's experiments showed that atoms have a dense concentration of particles in the center (nucleus), with smaller, less dense particles (electrons) surrounding it. The experiments also revealed that there is seemingly empty space between the nucleus and the surrounding electrons. Signup and view all the answers