Phys 101 Lecture 17

What is physics?

• A type of mathematics

• A field of science in which we study the physical world

• A study of plants and animals

• A branch of chemistry

If the temperature drops as a reaction happens, it is a ______________ reaction.

• Endothermic

• Exothermic

Tags

NGSS.MS-PS1-4

When a physical change happens, the form changes, but the ______ doesn't.

• size

• shape

• molecular structure

Which 2 are examples of a physical changes? (check 2 )

• ice melting

• sodium and chlorine combining to make sodium chloride (salt)

• paper being cut into smaller pieces

• wood burning

This picture shows which sign that a chemical reaction happened?

• a powdery precipitate formed

• the temperature dropped

• energy changed (light and flames are produced)

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-4

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If energy is released, like in this combustion reaction, then it is an ______ reaction.

• Endothermic

• Exothermic

Tags

NGSS.HS-PS1-4

Which is the correct atom count? (Remember the coefficient applies to both the H and O atoms).

• 2 Hydrogen + 2 Oxygen

• 2 Hydrogen + 1 Oxygen

• 4 Hydrogen + 2 Oxygen

Tags

NGSS.MS-PS1-1

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Which is the correct count of the atoms in a carbon dioxide molecule?.

• 2 Carbon + 2 Oxygen

• 1 Carbon + 2 Oxygen

• 1 Carbon + 1 Oxygen

Tags

NGSS.MS-PS1-1

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Which are the reactants and which are the products?

• reactants = Carbon dioxide + water

  products = methane + oxygen

• reactants = methane + oxygen

  products = Carbon dioxide + water

Tags

NGSS.MS-PS1-2

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The frequency of sound waves determines

• the pitch of the sound.

• the loudness of the sound.

• the quality of the sound.

• the type of interference.