What is an Atom?
An atom is the basic unit of matter. It is the smallest particle of an element that retains the properties of that element. Atoms are made up of three subatomic particles: protons, neutrons, and electrons.
Structure of an Atom
Atoms consist of a nucleus, which contains protons and neutrons, and electrons that orbit the nucleus in energy levels or shells.
Protons
Protons have a positive charge and are located in the nucleus of the atom.
Neutrons
Neutrons have no charge and are also located in the nucleus of the atom.
Electrons
Electrons have a negative charge and orbit the nucleus in energy levels or shells.
Study Guide
- What is an atom?
- What are the three subatomic particles that make up an atom?
- Describe the structure of an atom.
- Where are protons and neutrons located?
- What is the charge of protons, neutrons, and electrons?
- How do electrons behave in an atom?
[Atom] Related Worksheets and Study Guides:
.◂Science Worksheets and Study Guides Second Grade. What is science?
Study Guide
What is science? 
Worksheet/Answer key
What is science? Worksheet/Answer key
What is science? Worksheet/Answer key
What is science? Vocabulary/Answer key
What is science?
Worksheet/Answer keyWorksheet/Answer keyWorksheet/Answer keyVocabulary/Answer keyThe resources above cover the following skills:
LIFE SCIENCE
Ecosystems: Interactions, Energy, and Dynamics
Obtain information from literature and other media to illustrate that there are many different kinds of living things and that they exist in different places on land and in water (e.g., woodland, tundra, desert, rainforest, ocean, river).
EARTH AND SPACE SCIENCE
Earth’s Systems
Make observations from media to obtain information about Earth’s events that happen over a short period of time (e.g., tornados, volcanic explosions, earthquakes) or over a time period longer than one can observe (e.g., erosion of rocks, melting of glaciers).
Collect and evaluate data to identify water found on Earth and determine whether it is a solid or a liquid (e.g., glaciers as solid forms of water; oceans, lakes, rivers, streams as liquid forms of water).