Chemical Changes Guided Lab

Chemical Changes Guided Lab

The lab has several parts. Pay attention and do your best!

Multiple Choice

Phase changes are chemical changes.

• True

• False

Multiple Choice

The study of matter and how substances interact with each other

• Chemistry

• Physics

• Biology

• Geology

Multiple Select

Physical changes may change the _______, ______,

or ______ of a substance.

• shape

• size

• form

• arrangement of atoms

Multiple Choice

Which of the following statements best describes what happened to the water in the passage?

• When the water was exposed to the heat, it

  transformed into a new substance and

  disappeared from the glass.

• The Sun gave the water energy, which

  caused it to change states of matter.

• The water gained energy from the Sun,

  which made it undergo chemical changes.

• The Sun’s energy broke chemical bonds in

  the water, causing it to transform from a

  solid, to a liquid, to a gas.

Multiple Choice

Asking yourself if new matter was formed is the best way to determine if a______ change has occurred.

• State of Matter

• Physical

• Chemical

• Phase

Multiple Choice

Which of the following is NOT true of a chemical change?

• Chemical bonds are broken

• The identity of a substance has changed

• The substance has only changed form

  or appearance

• It can sometimes be indicated by the

  presence of bubbles or rust

​On the back of your paper, jot down notes and drawings that will help you remember the meaning of these words from the

reading.

1. chemistry

2. physical change

3. state of matter

4. chemical change

5. chemical bonds

Take out your notebook. Take notes on the following video and study them.

Open Ended

What are the 5 ways to identify if a chemical reaction happened?

​Random student callout!

Explain what a chemical reaction is.

Step 1: Fill the graduated cylinder up with

20ml of water.

Step 2: Take ONE effervescence tablet and

break it up so that it will fit into the

graduated cylinder.

​

​Mini experiment

You just experienced a chemical change (chemical reaction). A chemical change happens when atoms are rearranged to create a new substance.

The bubbles, or production of a gas, happens when baking soda (sodium bicarbonate) and citric acid from the tablet react chemically in water.

They create sodium citrate, water, and carbon dioxide gas, which causes bubbles. As you can see new substances were formed.

Observation!

Write your observations about what happens to the matchstick.

Burning or explosions are also evidence that a chemical change has taken place.

The phosphorus and sulfur on the tip of the match are burned up during the chemical reaction and create light and heat energy.

There are 3 other pieces of evidence that prove a chemical

change or chemical reaction has taken place.

The 3rd example is called a precipitate. When two liquid are

combined together, but a solid is produced that solid is called a precipitate.

The 4th piece of evidence is an unexpected temperature change.


Often heat is released (exothermic) when elements or compounds are combined. This causes the temperature to rise.

Sometimes heat is absorbed (endothermic) when elements or compounds are combined. This causes the temperature to fall.

These changes in temperature prove a chemical reaction occurred.

Multiple Choice

A chemical reaction that causes heat to be released (temperature rise).

• Exothermic

• Endothermic

Multiple Choice

A chemical reaction that causes heat to be absorbed (temperature fall).

• Exothermic

• Endothermic

Lastly, sometimes an unexpected color change occurs when two chemicals are combined. This is evidence of a chemical change.

Rust is one example of an unexpected chemical

change.

Multiple Choice

The first experiment with the vinegar and baking soda.

• Endothermic

• Exothermic

Multiple Choice

The second experiment with the steel wool and vinegar.

• Endothermic

• Exothermic

Open Ended

Are these experiments examples of physical or

chemical changes?

Support your answer with evidence.

Multiple Choice

Which of the following would not be evidence of a chemical change?

• Unexpected color change

• Unexpected temperature

  change

• Precipitate was formed

• The size of the substance

  changed

Multiple Choice

Two substances were combined and immediately a gas was produced. What type of change is

happening?

• chemical

• physical

• electrical

• accidental

Multiple Choice

Plants use a process called photosynthesis to survive. What evidence proves this process is a

chemical change?

• Chloroplasts are green

• Chloroplasts change shape

• Sunlight is needed

• Chloroplasts produce a new

  substance

Drag and Drop

We can tell when a chemical reaction occurs by looking at the result. If the matter changes identity rather than just form, then a ​

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has occurred. When this happens ​

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are broken and formed. If a substance’s size, shape, or form changes then a ​

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has occurred. This happens when a change in ​

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has happened, and the substance changes between solid, liquid, and/or gas. This all falls under the study of matter and how substances interact with each other, or ​

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.​

Drag these tiles and drop them in the correct blank above

chemical change

chemical bonds

physical change

state of matter

chemistry

physics

biology