Question

1. list three physical properties of non - metals.
2. scroll down to metalloids. what is the most common metalloid?
3. what is the most useful property of a metalloid?
4. watch the video segment. why is boron used in fireworks and flares?

Explanation:

Non - metals have various physical properties. They are generally not shiny (dull in appearance). They are poor conductors of heat and electricity. Also, they tend to be brittle when in solid form.
For metalloids, silicon is a very common one. The most useful property of metalloids is their semiconductor property. Boron is used in fireworks and flares because it burns with a distinctive color.

Answer:

1. Dull appearance, poor heat conductors, poor electrical conductors.
2. Silicon.
3. Semiconductor property.
4. Because it burns with a distinctive color.