CCEA A-Level Chemistry 1110
Formulae, Equations and Amounts of Substance
Atomic Structure
Bonding
Intermolecular Forces and Structure
Shapes of Molecules and Ions
Redox
The Halogens
Acid-Base Titrations
Qualitative Tests
Formulae and Amounts of a Substance
Nomenclature and Isomerism in Organic Chemistry
Alkanes
Alkenes
Halogenoalkanes
Alcohols
Infrared Spectroscopy
Energetics
Kinetics
Equilibrium
Group II Elements and Their Compounds
Lattice Enthalpy, Entropy and Free Energy
Rates of Reaction
Equilibrium and Acid-Base Equilibria
Isomerism
Aldehydes and Ketones
Carboxylic Acids
Derivatives of Carboxylic Acids
Aromatic Chemistry
Spectroscopy and Chromatography
Volumetric Analysis
Transition Metals
Electrode Potentials
Amines
Amides and Polymers
Amino Acids and Proteins
Atomic Structure
Atomic number, mass number and the composition of ions
- 3 things to know
- Unit AS 1
Overview
Atomic number of an element and mass number of an atom.
What you need to know
Answer each one before you reveal it.
Define the mass number of an atom.
How is the number of neutrons in an atom found from its atomic and mass numbers?
Questions from this subtopic
Each one with the model answer underneath.
- 1
Define the atomic number of an element.
Model answer
The atomic number is the number of protons in the nucleus of an atom of that element.
- 2
Define the mass number of an atom.
Model answer
The mass number is the total number of protons and neutrons in the nucleus of that atom.
- 3
How is the number of neutrons in an atom found from its atomic and mass numbers?
Model answer
The number of neutrons is the mass number minus the atomic number.
- 4
In the notation ³⁵₁₇Cl, what does each number represent?
Model answer
The upper number 35 is the mass number and the lower number 17 is the atomic number.
- 5
Give the numbers of protons, neutrons and electrons in an atom of ⁵⁶Fe.
Model answer
An atom of ⁵⁶Fe has 26 protons, 26 electrons and 30 neutrons.
- 6
How does the electron count of a positive ion compare with that of its parent atom?
Model answer
A positive ion has fewer electrons than the neutral atom, one fewer for each unit of positive charge.
Other ways to work this
The same content, four other ways.
What is inside Levo
Six ways to work the same material.
Every question in Atomic Structure, on a schedule.
Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.
Or £46 a year, about £3.83 a month. Cancel anytime.