Atomic Structure Flashcards
What is the smallest unit of matter?
An atom.
True or False: Atoms can be divided into smaller particles.
True.
What are the three main subatomic particles?
Protons, neutrons, and electrons.
Fill in the blank: The nucleus of an atom contains ______ and ______.
protons; neutrons.
What is the charge of an electron?
Negative.
Which particle has a positive charge?
Proton.
What is the mass number of an atom?
The total number of protons and neutrons in the nucleus.
True or False: Neutrons have no charge.
True.
What determines the identity of an element?
The number of protons in the nucleus.
Which subatomic particle is found in energy levels around the nucleus?
Electron.
What is the relative mass of a neutron compared to a proton?
Approximately equal.
Fill in the blank: The atomic number of an element is equal to the number of ______ in its nucleus.
protons.
What is an isotope?
Atoms of the same element with different numbers of neutrons.
True or False: Isotopes have different chemical properties.
False.
What is the electron configuration of carbon?
1s² 2s² 2p².
What is the maximum number of electrons in the first energy level?
2.
Fill in the blank: The outermost electrons are called ______ electrons.
valence.
What is the significance of valence electrons?
They determine an element’s chemical properties and reactivity.
What is the role of neutrons in the nucleus?
To provide stability and reduce repulsion between protons.
What is the term for the energy levels in an atom?
Shells.
True or False: Electrons can exist in between energy levels.
False.
What is the principle that describes the arrangement of electrons in an atom?
Aufbau principle.
What does the term ‘ion’ refer to?
An atom that has gained or lost electrons and has a charge.
What is the difference between cations and anions?
Cations are positively charged ions; anions are negatively charged ions.
Fill in the blank: Atoms are electrically ______ when they have equal numbers of protons and electrons.
neutral.
What is the concept of atomic mass?
The weighted average mass of an element’s isotopes.
