Question

*identify if the following are physical (p) or chemical (c) characteristics:

1. ________ sodium (na) is a very reactive alkali metal.
2. ________ oxygen (o) is a gas.
3. ________ wood is flammable.
4. ________ a ruby is red.
5. ________ copper (cu) conducts electricity.
6. ________ water (h₂o) freezes at 0 degrees celsius.
7. ________ iron (fe) reacts with water to form rust.
8. ________ silver (ag) reacts with moisture in the air to form tarnish.
9. ________ the chalkboard is magnetic.
10. ________ sand and dirt are mixed in a flower pot.

Explanation:

• Chemical characteristic: A chemical characteristic (or property) is a characteristic of a substance that is observed during a chemical reaction, where the substance changes into a different substance. For example, reactivity (like sodium being reactive, wood being flammable, iron reacting to form rust, silver reacting to form tarnish).
• Physical characteristic: A physical characteristic (or property) is a characteristic of a substance that can be observed or measured without changing the substance's identity. Examples include state of matter (oxygen being a gas), color (ruby is red), conductivity (copper conducts electricity), freezing point (water freezes at 0°C), magnetism (chalkboard is magnetic), and simply being a mixture (sand and dirt mixed in a flower - pot, as no chemical change occurs in just mixing them).

Answer:

1. C
2. P
3. C
4. P
5. P
6. P
7. C
8. C
9. P
10. P