I would say the answer is emissions. These are the particles that are not supposed to be present in air but due to the production of different substances from humans daily activities these substances go with the air we breath. Hope this helped.

7 0

3 years ago

If an atom has three shell and number of valence electrons are two. Is this element metal

cluponka [151]

Answer:

Metal

Element: Calcium

Valency: 2

Explanation:

To find the element, let's use the periodic table. (Look below)

We already went past 3 shells, just need the 2 electrons after it.

Just skip to the 4th row and count 2 to the right

We end up at Calcium.

Calcium is a metal and we're also on the alkaline earth metals column.

Calcium will need to lose 2 electrons to reach stability, so the valency is 2.

3 0

3 years ago

Describe a group of family on the periodic table

lana66690 [7]

Metals are all in the center of the periodic table and are all made up of metals

6 0

3 years ago

Read 2 more answers

Identify the following changes as physical or chemical.

andrezito [222]

Answer:

physical

Explanation:

5 0

3 years ago