Year 10 - Science
Atomic structure (negligible electron mass)
Atomic structure and the periodic table
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This pupil-friendly study guide includes a unit summary, clear notes, common mistakes, and quick questions with answers.
Unit Summary
This unit covers the atomic model, relative atomic mass, isotopes, and the structure of the modern periodic table. It explains how atomic structure influences element positioning, properties, and reactivity. The focus is on identifying trends and using models to develop scientific explanations.
Lesson Summary
You will learn to describe the physical characteristics of atoms, protons, neutrons and electrons.
Key Notes
- Electrons have a relative charge of -1 and roughly a relative atomic mass of 1/1835 (negligible).
- Protons are found in the atomic nucleus, have a relative electric charge of +1, and a relative mass of 1.
- Neutrons are found in the atomic nucleus, have no electric charge, and a relative mass of 1.
- An atom has no electric charge as it contains equal numbers of protons and electrons to balance the charge.
- The atom has a nucleus surrounded by electrons, with the nuclear radius much smaller than that of the atom.
Vocabulary To Learn
- electron: An electron is a subatomic particle with a negative charge and a very small relative mass of 1/1835 (negligible).
- proton: A proton is a subatomic particle with a positive charge and a relative atomic mass of 1.
- neutron: A neutron is a subatomic particle with no charge and a relative atomic mass of 1.
- nucleus: A nucleus is found in the centre of an atom. It consists of protons and neutrons. It is significantly smaller in size than the atom.
- subatomic: Anything that is smaller than an atom. There are three subatomic particles called electrons, protons and neutrons.
Common Mistakes To Avoid
- Students often struggle with the idea of how small an atom actually is. In contrast, how small the nucleus is, relative to the size of the atom.
3 Quick Questions (With Answers)
1. Explain the scientific idea in this lesson using two key points.
Electrons have a relative charge of -1 and roughly a relative atomic mass of 1/1835 (negligible). Protons are found in the atomic nucleus, have a relative electric charge of +1, and a relative mass of 1.
2. Define this scientific word and use it in context. 'electron'
An electron is a subatomic particle with a negative charge and a very small relative mass of 1/1835 (negligible). Include the word in a full scientific explanation, not as a single label.
3. Correct this common scientific misunderstanding.
Mistake: Students often struggle with the idea of how small an atom actually is. In contrast, how small the nucleus is, relative to the size of the atom. Correction: The use of units and numbers to show the difference in size, e.g. the atom is approximately 10, 000 times larger than the nucleus. The radius of the atom is 0.1nm and the nucleus very small compared to that of the atom.
More Lessons In This Unit
- Atomic number and mass number Study Guide
- Atomic structure (very small electron mass) Study Guide
- Atoms, elements and compounds Study Guide
- Developing a model for atoms Study Guide
- Development of the periodic table Study Guide
- Isotopes Study Guide
- Isotopes and relative atomic mass Study Guide
- Modern periodic table and electron configuration Study Guide
- Relative formula mass Study Guide
- Using the periodic table: atomic and mass number Study Guide
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