Atomic Theory

An atom is electrically neutral because

In a glass tube, electrical current passes from the negative electrode or

Because any element used in the cathode produced electrons, scientists concluded that

Who was the schoolmaster who studied Chemistry and proposed an atomic theory?

According to the Bohr model, the electron of a hydrogen atom circles the nucleus

The forces that hold the particles in the nucleus together are called

Most of the volume of an atom is occupied by the

The deflection of cathode rays in Thomson’s experiments showed electrons are

The nucleus of most atoms is composed of

Louis de Broglie’s research suggested that

Because a few positive particles bounced back from the foil Rutherford concluded that they were

Rutherford fired positive particles at metal foil and concluded most of the mass of an atom was

In experiments on electricity & matter, an electrical current passed through a tube containing

Milikan's experiments

Because most particles fired at metal foil passed straight through, Rutherford concluded that

As the mass number of the isotopes of an element increases, the number of protons

A nuclear particle that has about the same mass as a proton, but with no charge, is an

Rutherford’s experiment led to the discovery of the

According to Bohr’s theory, an excited atom would