What kind of control like scientific?
Answer:
Cement is a combination of calcium, silicone, aluminum, iron and lots of other ingredients to make side walks, home made crafts, etc. The person who invented concrete is Joseph Aspdin.
Explanation:
Stable isotopes are not radioactive nor dangerous.
Unstable isostopes are radioactive and have different mass of the element.
Answer:
a. atoms are indivisible. ... atoms can not be destroyed in chemical reactions.
Explanation:
Hope this helped :D
Answer:
I think this is how you draw it, but I'm not entirely sure.
Explanation:
Screenshot below: