Here are the answers to help you complete your Grade 7 Natural Sciences worksheet.
1.1. What does 'physical property' mean?
A physical property is a characteristic of a material that we can observe or measure without changing what the material is made of. For example, you can look at the color or feel the hardness of a rock without turning it into something else.
1.2. Complete the following table:
Here are five common physical properties with their descriptions and examples:
| Physical property | Description | Example |
| :--- | :--- | :--- |
|
a) Hardness | How difficult it is to scratch or dent the material. | Diamond is very hard; chalk is soft. |
|
b) Density | How heavy a material is for its size (mass per volume). | Lead is dense (heavy); Styrofoam has low density (light). |
|
c) Melting Point | The temperature at which a solid turns into a liquid. | Ice melts at 0°C; Iron melts at very high temperatures. |
|
d) Electrical Conductivity | The ability of a material to let electricity flow through it. | Copper wires conduct electricity well; plastic does not. |
|
e) Thermal Conductivity | The ability of a material to let heat flow through it. | Metal pots conduct heat to cook food; wood handles stay cool. |
*(Note: Other acceptable answers could include
Color,
Texture,
Magnetism, or
Boiling Point.)*
Parent Tip: Review the logic above to help your child master the concept of 7 ns 2 worksheet.
