Atomic Structure Quiz

What does the atomic number of an ion indicate?

How do you determine the number of electrons in a positive ion (cation)?

In the ion 24Mg2+, how many neutrons are present?

What calculation is used to find the number of neutrons in an atom?

If an ion has an atomic number of 16 and a mass number of 32, what is the total number of electrons in the ion if it has a -2 charge?

What particles are located in the nucleus of an atom?

What is the charge of a proton?

In a neutral atom, how are the number of electrons related to the number of protons?

How is the mass number of an atom defined?

What is the mass of an electron relative to a proton?

Which of the following statements about atomic composition is correct?

What is the relationship between mass number and atomic number for an atom represented as 7Li?

Where do electrons predominantly exist in an atom?

Atomic Structure

Atoms are composed of protons, neutrons, and electrons.
Protons and neutrons are found in the nucleus, which is very small and dense, containing most of the atom's mass.
Electrons orbit the nucleus in shells/orbitals, occupying a large region of space, meaning most of an atom's volume is empty space.
Protons have a positive charge, neutrons are neutral, and electrons have a negative charge.
Relative masses and charges are: Proton (1,+1), Neutron (1,0), Electron (0.0005,-1).

Representing Atomic Composition

Nuclear symbols use mass number (A) and atomic number (Z).
Mass number (A) is the total number of nucleons (protons + neutrons).
Atomic number (Z) is the number of protons, uniquely identifying an element.

Determining Subatomic Particles in Neutral Atoms

Number of protons = Atomic number (Z)
Number of electrons = Number of protons (in neutral atoms)
Number of neutrons = Mass number (A) - Atomic number (Z)

Example: 7Li Atom

Atomic number (Z) = 3, so 3 protons.
Number of electrons = 3 (neutral atom)
Mass number (A) = 7, so 7 - 3 = 4 neutrons.

Ions and Subatomic Particles

Ions are atoms with unequal numbers of protons and electrons.
- Anions (negative ions) have more electrons than protons.
- Cations (positive ions) have fewer electrons than protons.
To find electrons in an ion:
- For cations (positive): Electrons = Atomic number - ion charge.
- For anions (negative): Electrons = Atomic number + ion charge

Example: 7Li+ Ion

Atomic number (Z) = 3, so 3 protons.
Ion charge is +1, so electrons = 3 - 1 = 2 electrons.
Mass number (A) = 7, so 7 - 3 = 4 neutrons.

Test your knowledge on atomic structure and subatomic particles. This quiz covers the composition of atoms, including protons, neutrons, and electrons, as well as how to represent atomic composition using nuclear symbols. Challenge yourself with questions based on the arrangement and properties of these fundamental particles.