The chart shows how materials can change chemically. Why are these changes classified as chemical changes?

• New substances formed

• Materials take different shapes

• Temperature affects the objects

• Some energy is absorbed

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NGSS.MS-PS1-2

NGSS.MS-PS1-5

When baking soda reacts with vinegar, bubbles form and the container feels cold. This is an example of:

• Exothermic reaction - energy is released.

• Endothermic reaction - energy is absorbed from the surroundings.

• Neither endothermic nor exothermic - no energy transfer occurs.

• The coldness is due to the vinegar, not the reaction itself.

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NGSS.MS-PS1-4

NGSS.MS-PS3-4

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A partial periodic table is shown below. Use the periodic table to predict if an ionic or covalent bond forms. (Hint: How do we know if it is ionic or covalent?) Example NaCl-What is the bond, how do you know?

Answer explanation

Metal + Metal= Metallic Bonding

Nonmetal +Nonmetal= Covalent

Nonmetal + Metal= Ionic

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NGSS.HS-PS1-1

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How many different elements are involved in the chemical reaction shown below? Ca + 2H₂O → Ca(OH)₂ + H₂

The formation of an ionic bond involves the

• transfer of electrons.

• sharing of neutrons.

• transfer of neutrons.

• sharing of protons.

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NGSS.MS-PS1-1

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NGSS.MS-PS1-5

The formation of a covalent bond involves the

• transfer of electrons.

• sharing of electrons.

• transfer of neutrons.

• sharing of protons.

Tags

NGSS.MS-PS1-1

Which type of matter can be separated by physical means?

• atom

• element

• compound

• mixture

The chart below lists samples of three materials. Classify each sample in the chart as an element, a compound, or a mixture by typing on the line.

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​ ​

​ ​

Answer explanation

List them in order and seperate responses with a comma.

Tags

NGSS.MS-PS1-1

The equation below shows the products formed with a solution of silver nitrate (AgNO₃) reacts with a solution of sodium chloride (NaCl). AgNO₃ + NaCl → NaNO₃ + AgCl (Reactants) ⇒ (Products) In this equation, the total mass of the reactants is

• greater than the total mass of the products

• equal to the total mass of the products

• equal to the mass of AgCl

• less than the mass of AgCl

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

The diagram below represents two atoms in a molecule of oxygen that combine chemically with one atom of carbon to form a carbon dioxide molecule.

• a mixture

• an element

• a solution

• a compound

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-2

NGSS.MS-PS1-5