Answer:
proton :
a particale or atom containing a postive charge
nuutron
a particale or atom that contains a negative charge
electron :
a particale or atom with a negative chrage.
Explanation:
proton:
a stable subatomic particle occurring in all atomic nuclei, with a positive electric charge equal in magnitude to that of an electron, but of opposite sign.
nuetron:
a subatomic particle of about the same mass as a proton but without an electric charge, present in all atomic nuclei except those of ordinary hydrogen.
elcetron:
a stable subatomic particle with a charge of negative electricity, found in all atoms and acting as the primary carrier of electricity in solids.
Answer:
Here:
Explanation:
To familiarize students with experimental apparatus, the scientific method, and methods of data analysis so that they will have some idea of the inductive process by which the ideas were originated. To teach how to make careful experimental observations and how to think about and draw conclusions from such data.
Answer:
The mass fraction of ferric oxide in the original sample :
Explanation:
Mass of the mixture = 3.110 g
Mass of 
Mass of 
After heating the mixture it allowed to react with hydrogen gas in which all the ferric oxide reacted to form metallic iron and water vapors where as aluminum oxide did not react.

Mass of mixture left after all the ferric oxide has reacted = 2.387 g
Mass of mixture left after all the ferric oxide has reacted = y

The mass fraction of ferric oxide in the original sample :

If a sample is packed poorly, the sample will not heat evenly and will take longer to melt.
Answer:
Gravity is very important for us,animals and plants. We could not survive Earth without it. The sun's gravity keeps Earth in orbit around it, keeping us a good distance away from it (the sun). Gravity is holding down our atmosphere and the air we need to breathe along with it.