SCI.PS - Unit 3 - Matter and Its Changes (Systemwide)

The windows of your school are made of glass. Which of the following statements describes the motion of the molecules that make up the glass?

• The molecules of the glass are never moving.

• The molecules of the glass are always moving.

• The molecules of the glass move only when the sun warms the window.

• The molecules of the glass move only when the window is being opened or closed.

Karla left a glass of water at 43°C next to a glass of water at 10°C in a 23°C room overnight. The temperature of the two glasses of water the next day will be about

• 10°C

• 15°C

• 23°C

• 32°C

Directions: Drag the answers to the correct boxes. The pictures below show the arrangement of particles in three phases of matter. Match the picture with the correct phase of matter.

• Arrangement of particles in gas

• 
• Arrangement of particles in liquid

• 
• Arrangement of particles in solid

• 

What happens to the molecules of a liquid in a thermometer when heated?

• A. Water molecules are pushed into the thermometer.

• B. Heat molecules push the molecules of the liquid upward.

• C. Heat causes the molecules of the liquid to go farther apart.

• D. The molecules of the liquid break down into atoms and take up more space.

When ice melts, a(n) ---

• A. chemical change rearranges the molecules of water

• B. electrical change prevents current flow through the resulting solution

• C. physical change produces a new state of matter

• D. thermal change releases thermal energy to the environment

A student mixes two different liquids together. After mixing the liquids, a solid substance forms that cannot be turned back into the starting liquids. The student claims that a chemical reaction occurred. Why is the student correct?

• Because a solid substance is always formed during a chemical reaction

• Because a new substance is always formed during a chemical reaction

• Because a chemical reaction always occurs when two substances are mixed together

• Because the products of a chemical reaction can never be turned back into the starting substances

Identify the type of change for each of the following scenarios:

A person boils water on the stove.

• A) Physical Change

• B) Chemical Change

Identify the type of change for each of the following scenarios:

Firewood burns in a fireplace.

• A) Physical Change

• B) Chemical Change

Identify the type of change for each of the following scenarios:

Chemicals inside a bag react to form an instant cold pack.

• A) Physical Change

• B) Chemical Change

Which of the following equations correctly shows the conservation of mass?

• HgO → Hg+O₂

• BaSO₄+C → BaS+CO

• H₂SO₄+2 KOH → K₂SO₄+2 H₂O

• NiCl₂+2 NaOH → 3(OH)₂+ NaCl