Which of the Following Observations Is/are Examples of Physical Change $^{\circ}$

question 9

Multiple Choice

Which of the following observations is/are examples of physical change?
1) The density of water decreases when it solidifies.
2) Aluminum melts when heated above 660 $^{\circ}$ C.
3) Hydrogen peroxide (H₂O₂) decomposes to water and oxygen.

• A) 1 only
• B) 2 only
• C) 3 only
• D) 1 and 2
• E) 1,2,and 3

---

Definitions:

Complimentary Closing

A polite phrase used to conclude a letter or message before the sender's signature, such as "Sincerely" or "Best regards".

Signature Block

The writer’s name and business title found four lines below the complimentary closing in a business letter.

Body of the Letter

The main text or content of a letter, located between the greeting or salutation and the closing, where the primary message is communicated.

Subject Line

The headline or title found at the beginning of an email or document, summarizing its content or purpose.