## Matter and Its Interactions

#### Students who demonstrate understanding can:

Develop models to describe the atomic composition of simple molecules and extended structures. MS-PS1-1

Clarification Statement and Assessment Boundary

Clarification Statement: Emphasis is on developing models of molecules that vary in complexity. Examples of simple molecules could include ammonia and methanol. Examples of extended structures could include sodium chloride or diamonds. Examples of molecular-level models could include drawings, 3D ball and stick structures, or computer representations showing different molecules with different types of atoms.

Assessment Boundary: Assessment does not include valence electrons and bonding energy, discussing the ionic nature of subunits of complex structures, or a complete description of all individual atoms in a complex molecule or extended structure is not required.

##### Science and Engineering Practices

Developing and Using Models

Modeling in 6–8 builds on K–5 experiences and progresses to developing, using, and revising models to describe, test, and predict more abstract phenomena and design systems.

##### Disciplinary Core Ideas

PS1.AStructure and Properties of Matter

##### Crosscutting Concepts

Scale, Proportion, and Quantity

### Common Core State Standards Connections

ELA/Literacy
• RST.6-8.7 - Integrate quantitative or technical information expressed in words in a text with a version of that information expressed visually (e.g., in a flowchart, diagram, model, graph, or table). (MS-PS1-1)
Mathematics
• 6.RP.A.3 - Use ratio and rate reasoning to solve real-world and mathematical problems, e.g., by reasoning about tables of equivalent ratios, tape diagrams, double number line diagrams, or equations. (MS-PS1-1)
• 8.EE.A.3 - Use numbers expressed in the form of a single digit times an integer power of 10 to estimate very large or very small quantities, and to express how many times as much one is than the other. (MS-PS1-1)
• MP.2 - Reason abstractly and quantitatively. (MS-PS1-1)
• MP.4 - Model with mathematics. (MS-PS1-1)

National Science Teaching Association
405 E Laburnum Ave Ste 3, Richmond, VA 23222
(T) 703.243.7100 (F) 703.243.7177