Chemistry Unit 3 - Atomic Structure

Front

What is the mass number of an atom?

Back

The mass number is the total number of protons and neutrons in an atom's nucleus.

Front

What is an isotope?

Back

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

Front

How do you calculate the average atomic mass of an element?

Back

Average atomic mass is calculated by taking the weighted average of the masses of its isotopes based on their natural abundance.

Front

What is the significance of the atomic number?

Back

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

Front

Describe the Bohr model of the atom.

Back

The Bohr model depicts the atom as a small, positively charged nucleus surrounded by electrons that travel in circular orbits at fixed distances.

Front

What is the electron cloud model?

Back

The electron cloud model describes the regions around the nucleus where electrons are likely to be found, rather than fixed orbits.

Front

What did J.J. Thomson discover about the atom?

Back

J.J. Thomson discovered the electron and proposed the Plum Pudding Model, which suggested that atoms are made of a positively charged 'soup' with negatively charged electrons scattered throughout.

Front

What is the difference between mass number and atomic mass?

Back

Mass number is a whole number representing the total number of protons and neutrons, while atomic mass is a weighted average of all isotopes of an element, expressed in atomic mass units (AMU).

Front

What is the role of neutrons in an atom?

Back

Neutrons contribute to the mass of an atom and help stabilize the nucleus by offsetting the repulsive forces between protons.

Front

What is a chemical symbol?

Back

A chemical symbol is a one or two-letter notation used to represent a chemical element, derived from its name in English or Latin.