TEKS Addressed:   6.1A, 6.1B, 6.2A, 6.2B, 6.2C, 6.2D, 6.2E, 6.3A, 6.3B, 6.3C, 6.3D, 6.4A, 6.4B, 6.5A, 6.5C 

Introduction

This unit bundles Student Expectations that address the differences between elements and compounds and the evidence of chemical change. Elements are the simplest pure substance made up of one kind of matter, and compounds are pure substances composed of two or more elements. In a chemical change, the elements of the original substances are rearranged and grouped into a different order, and the new substance(s) have different properties from those of the original substances.

Prior to this Unit

• Grade 3

  • 3.5A – Measure, test, and record physical properties of matter, including temperature, mass, magnetism, and the ability to sink or float.

• Grade 4

  • 4.5A – Measure, compare, and contrast physical properties of matter, including mass, volume, states (solid, liquid, gas), temperature, magnetism, and the ability to sink or float.

  • 4.5B – Compare and contrast a variety of mixtures, including solutions.

• Grade 5

  • 5.5A – Classify matter based on measurable, testable, and observable physical properties, including mass, magnetism, physical state (solid, liquid, and gas), relative density (sinking and floating using water as a reference point), solubility in water, and the ability to conduct or insulate thermal energy or electric energy.

  • 5.5B – Demonstrate that some mixtures maintain physical properties of their ingredients such as iron filings and sand and sand and water.

During this Unit

This is students’ first experience with the concepts of elements, compounds, and chemical change. Students learn that an element is the simplest pure substance made up of one kind of matter, which is represented by a chemical symbol on the Periodic Table, and a compound is a pure substance composed of two or more elements and represented by a chemical formula. Students use scientific practices and a variety of tools to investigate elements, compounds, and the formation of new substances by using the evidence of a possible chemical change. Additionally, students communicate and discuss their observations and record and organize data in their notebooks. Furthermore, students analyze and interpret information to construct reasonable explanations based on evidence from their investigations and communicate valid conclusions (supported by collected data). Students continue to demonstrate safe practices as outlined in the Texas Education Agency-approved safety standards and consider environmentally appropriate and ethical practices with resources during investigations.

After this Unit

In Unit 02, students will investigate properties of matter. In the context of later units, students will study the elements that make up the largest portion of solid Earth, living matter, oceans, and the atmosphere. In subsequent grades, students will learn about the differences in elements and compounds at molecular and atomic levels.