Unit 1: Key concepts and Assessment Review

What key concepts (pick two) will help make sense of this evidence: Every time we saw a substance with different properties we saw that it had different molecular arrangements.

• During a chemical reaction, one or more reactants change into one or more different substances with a different arrangement of atoms.

• Substances have different properties because they are made of different groups of atoms. These groups vary in the type or number of atoms that make up the group.

• During a chemical reaction, all of the atoms that make up the reactants rearrange to form the products.

• Things that are too small (or too large) to see can be studied with models.

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-2

What key concept will help make sense of this evidence and claim:

The reddish brown substance was not the same as the iron pipe or fertilizer substance.

• Different substances have different properties.

• During a chemical reaction, atoms do not change from one type to another and do not change in number.

• In a chemical reaction atoms are not destroyed and are not created.

The diagram above shows the repeating groups of atoms that make up two samples. Both samples are red powdery solids at room temperature. Will the other properties of the two samples be the same or different? (Examples of properties are smell, color, and the temperature at which a substance melts.)

• The other properties will be different because there are more repeating groups of atoms in Sample 1.

• The other properties will be the same because both samples are red at room temperature.

• The other properties will be the same because both samples are powdery solids at room temperature.

• The other properties will be same because the repeating groups of atoms that make up the two samples are the same.

The diagram above shows the repeating groups of atoms that make up two samples. Both samples are solids at room temperature. Will the other properties of the two samples likely be the same or different? (Examples of properties are smell, color, and the temperature at which a substance melts.)

• The other properties will likely be different because there are more repeating groups of atoms in Sample 2.

• The other properties will likely be different because the repeating groups of atoms that make up the two samples have different numbers of atoms.

• The other properties will likely be the same because the repeating groups of atoms that make up the two samples have the same types of atoms.

• The other properties will likely be the same because both samples are solids at room temperature.

What key concept will help make sense of this evidence and claim: Atoms and molecules are very small, but they can make up much larger objects, like diamonds.

• During a chemical reaction, one or more reactants change into one or more different substances with a different arrangement of atoms.

• Groups of atoms repeat to make up a substance. (More of the same repeating group, means more of the same substance.).

• In a chemical reaction atoms are not destroyed and are not created.

What key concept will help make sense of this evidence and claim:

The reddish-brown substance is not the same as the fertilizer or pipe substance.

• During a chemical reaction, atoms do not change from one type to another and do not change in number.

• Substances have different properties because they are made of different groups of atoms. These groups vary in the type or number of atoms that make up the group.

• Things that are too small (or too large) to see can be studied with models.

The diagram above shows the repeating groups of atoms that make up two samples. Will the properties of the two samples likely be the same or different? (Examples of properties are smell, color, and the temperature at which a substance melts.)

• The properties will likely be different because there are more repeating groups of atoms in Sample 2.

• The properties will likely be different because the repeating groups of atoms that make up each sample are different.

• The properties will likely be the same because the repeating groups of atoms that make up the two samples have one of the same types of atoms.

• The properties will likely be the same because the repeating groups of atoms that make up the two samples have the same number of atoms.

Which key concept will help explain the claim and evidence:

When we mixed two clear liquids in class, we saw two new substances form that were white solids. (See the atomic-scale models.)

• Groups of atoms repeat to make up a substance. (More of the same repeating group, means more of the same substance.)

• During a chemical reaction, atoms do not change from one type to another and do not change in number.

• During a chemical reaction, one or more reactants change into one or more different substances with a different arrangement of atoms.

Which key concepts help us make sense of this evidence or claim:

Rust was not the only substance created when fertilizer and iron chemically reacted.

• Different substances have different properties.

• During a chemical reaction, atoms do not change from one type to another and do not change in number.

• During a chemical reaction, *all* of the atoms that make up the reactants rearrange to form the products.

Which key concepts (pick 2) help us make sense of the claim and evidence:

When we looked at many different chemical reactions, we counted the same number of atoms before a reaction and after the reaction.

• During a chemical reaction, all of the atoms that make up the reactants rearrange to form the products

• Substances have different properties because they are made of different groups of atoms.

• During a chemical reaction, atoms do not change from one type to another and do not change in number.