Atomic Theory

Front

Who was the first contributor to the atomic theory?

Back

Democritus proposed that matter is made up of small, indivisible particles called atoms.

Front

What is the name of this element? (Given: Argon)

Back

Argon is a noble gas with the atomic number 18.

Front

If an atom has an atomic number of 6 and is neutral, how many electrons does it have?

Back

6 electrons, as the number of electrons equals the atomic number in a neutral atom.

Front

Which model of the atom proposed that atoms were positive spheres with negative electrons in them?

Back

The Plum Pudding Model, proposed by J.J. Thomson, describes atoms as a mix of positive and negative charges.

Front

What is the correct symbol for a Bromine ion that gains 1 electron?

Back

Br^-1, indicating it has gained an electron and has a negative charge.

Front

Define atomic number.

Back

The atomic number is the number of protons in the nucleus of an atom, which determines the element's identity.

Front

What is the charge of a neutron?

Back

Neutrons have no charge; they are neutral particles found in the nucleus of an atom.

Front

What is the difference between an atom and an ion?

Back

An atom is neutral, while an ion has a net charge due to the loss or gain of electrons.

Front

What does the term 'isotope' mean?

Back

Isotopes are variants of a chemical element that have the same number of protons but different numbers of neutrons.

Front

What is the significance of the electron cloud model?

Back

The electron cloud model describes the regions around the nucleus where electrons are likely to be found, emphasizing their wave-like behavior.