It should be D, cells are parts, tissue is part and organ is part of a system.
Magnesium + Hydrocloric acid -> Magnesium chloride + hydrogen
You can observe a single displacement reaction
"Describe to show that the has formed is hydrogen"
I don't know what you mean. I can show the chemical equation though.
Mg(s) + 2 HCl(aq) --> MgCl 2(aq) + H 2(g)
Answer:
gain or loses electrons.
Explanation:
Because the atom need to be balanced.