Science Grade 8

Which diagram below represents a pure substance?

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Tags

NGSS.MS-PS1-1

Which of the following diagrams correctly represents the organization of matter by composition?

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Students are given a solid sample and asked to determine whether the sample is an element, compound, or mixture. One student observes that the sample is made up of particles of different colors, sizes, and shapes. When the students break off a piece of the sample, they notice that some particles are softer than others and some shine while others appear dull. What can the students conclude about their sample?

• A. It is an element.

• B. It is a compound.

• C. It is a homogeneous mixture.

• D. It is a heterogeneous mixture.

Samples of the air we breathe that were taken from different parts of the world have all been found to contain about 78% nitrogen, 21% oxygen, 0.9% argon, 0.03% carbon dioxide, and 0.07% other gases. Based on this analysis, which is the correct classification for air?

• A. element

• B. compound

• C. homogenous mixture

• D. heterogeneous mixture

Which of the following models best represents a mixture?

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The following is classfied as?

• Heterogeneous Mixture

• Compound

• Element

• Homogenous Mixture

Tags

NGSS.MS-PS1-2

The following is classfied as?

• Heterogeneous Mixture

• Element

• Compound

• Homogenous Mixture

Tags

NGSS.MS-PS1-1

The following is classfied as?

• Heterogeneous Mixture

• Element

• Compound

• Homogenous Mixture

Tags

NGSS.MS-PS1-1

The following is classfied as?

• Heterogeneous Mixture

• Element

• Compound

• Homogenous Mixture

A chemical equation for the reaction calcium hydroxide, Ca(OH)₂ and sulfuric acid H₂SO₄ is shown. The masses of the reactants and products are given in grams. How many grams of sulfuric acid were used in the reaction?

• 62g

• 98g

• 36g

• 100g

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5