Atomic Number

The atomic number of an element is the number of protons found in the nucleus of an atom. It is a unique identifier for each element and is used to organize the elements on the periodic table. The atomic number determines the chemical properties of an element, as each element has a distinct number of protons.

Study Guide

Definition: The atomic number of an element is the number of protons in the nucleus of an atom.
Significance: It is a unique identifier for each element and determines its chemical properties.
Location: The atomic number is found above the element's symbol on the periodic table.
Relation to Electrons: The atomic number also represents the number of electrons in a neutral atom of the element.
Organization: Elements are arranged in ascending order of atomic number on the periodic table.
Examples: Hydrogen has an atomic number of 1, oxygen has an atomic number of 8, and gold has an atomic number of 79.
Chemical Properties: Elements with the same atomic number have similar chemical properties, and elements with different atomic numbers have different chemical properties.

Understanding the concept of atomic number is crucial for comprehending the organization and properties of elements in chemistry.

◂Science Worksheets and Study Guides Second Grade. What is science?

Vocabulary/Answer key

What is science?

The 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).