SRA #6

Two unknown substances are mixed together. What evidence supports that a pure substance is formed?

• The starting substances retain their physical properties after being mixed.
• One type of substance forms with properties that differ from the original.
• Heat is generated as a result of mixing the two substances.
• A solid is visible within a liquid solution.

Tags

NGSS.MS-PS1-2

Which diagram represents a mixture forming from two elements?

• A
• B
• C
• D

Tap water contains water molecules and particles such as chlorine, fluoride, and sodium that are added during the cleaning process. Is tap water considered a pure substance or a mixture, and why?

• Pure substance; it is safe to drink.
• Pure substance; it is needed for basic body functions.
• Mixture; it can be purified by boiling.
• Mixture; it is made of compounds and particles.

Which option correctly classifies each figure as a compound, element, or mixture?

• Figure 1: element; Figure 2: compound; Figure 3: mixture
• Figure 1: element; Figure 2: mixture; Figure 3: compound
• Figure 1: compound; Figure 2: element; Figure 3: mixture
• Figure 1: compound; Figure 2: mixture; Figure 3: element

Tags

NGSS.MS-PS1-1

How is the substance best classified?

• compound
• element
• mixture
• molecule

Tags

NGSS.MS-PS1-1

Which forms of matter are considered pure substances?

• elements only
• mixtures only
• compounds and mixtures
• elements and compounds

How is the sample of matter best classified?

• compound
• diatomic element
• mixture
• monoatomic element

Tags

NGSS.MS-PS1-1

Which substance represents an element?

• carbon dioxide (CO2)
• copper metal (Cu)
• salt (NaCl)
• water (H2O)

How is air best classified?

• compound
• element
• mixture
• pure substance

Tags

NGSS.MS-PS1-1

What can be concluded based on the models, and why?

• Substance P is a compound because all the atoms are the same.
• Substance R is a mixture because all the compounds have similar properties.
• Substance Q is an element because two different atoms are bonded to each other.
• Substance R is a mixture because it is a combination of two elements and a compound.

Tags

NGSS.MS-PS1-1