Path to Mastering LT 2.1 - Atomic structure

What is the charge of a proton?

• Neutral

• Positive

• Negative

• No charge

Answer explanation

A proton carries a positive charge, which is fundamental to its role in atomic structure. This distinguishes it from neutrons, which are neutral, and electrons, which have a negative charge.

Where are neutrons located in an atom?

• In the electron cloud

• In the nucleus

• Orbiting the nucleus

• Outside the atom

Answer explanation

Neutrons are located in the nucleus of an atom, along with protons. They are not found in the electron cloud, orbiting the nucleus, or outside the atom.

Which subatomic particle has a relative mass of approximately 1 amu (atomic mass unit)?

• Electron

• Proton

• Neutron

• Both B and C

Answer explanation

Protons and neutrons both have a relative mass of approximately 1 amu, while electrons have a negligible mass. Therefore, the correct answer is 'Both B and C'.

Explain why electrons are not considered when calculating the mass of an atom.

• Electrons have a positive charge that cancels out their mass.

• Electrons are too small and have negligible mass compared to protons and neutrons.

• Electrons are located outside the nucleus and do not contribute to atomic mass.

• Electrons are not part of the atom's structure.

Answer explanation

Electrons are too small and have negligible mass compared to protons and neutrons, which are the primary contributors to an atom's mass. Therefore, when calculating atomic mass, electrons are not considered.

Compare the roles of protons and electrons in determining the identity and charge of an atom.

• Protons determine the identity, while electrons determine the charge.

• Electrons determine the identity, while protons determine the charge.

• Both protons and electrons determine the identity and charge.

• Neither protons nor electrons determine the identity or charge.

Answer explanation

Protons, found in the nucleus, define the element's identity (e.g., hydrogen has 1 proton). Electrons, which orbit the nucleus, influence the atom's charge; an imbalance between protons and electrons results in a charged ion.

Describe the overall structure of an atom, including the arrangement of protons, neutrons, and electrons.

• Protons and neutrons are in the nucleus, while electrons orbit the nucleus in the electron cloud.

• Electrons and protons are in the nucleus, while neutrons orbit the nucleus.

• Neutrons and electrons are in the nucleus, while protons orbit the nucleus.

• All particles are randomly distributed throughout the atom.

Answer explanation

The correct choice states that protons and neutrons are in the nucleus, while electrons orbit the nucleus in defined paths. This accurately describes the atomic structure, distinguishing the roles of each particle.

Match the following

• Negative

• Electron

• Neutral (No Charge)

• Proton

• Positive

• Neutron

Answer explanation

Protons have a positive charge, electrons carry a negative charge, and neutrons have no charge (neutral).

Smallest of the 3 subatomic particles

• protons

• neutrons

• electrons

Answer explanation

Both protons and neutrons have a mass of 1 amu while electrons have a much smaller mass in comparison (0.0005 amu).