Can you please translate it to english?
Answer:
Chemistry helps in improving the quality of our life, it helps in improving food production, building & construction, military and space science, clothing materials, medicine and transportation.
I'd say it's A because while the energy cannot be lost, it can not be 100% efficient because if it was we wouldn't have to worry about energy.
Answer:
Depends on what are you refering to
Explanation:
So depending on what you are looking for (your question is quite vauge)
there are 5 atoms of the comopound (K2CO3)
within that compound, there are 2 atoms of Potassium and 1 atom of Carbonate. Within Carbonate there are 4 atoms (1 carbon and 3 oxygens)
so answers may be
5, 15, or 25.
I hope this helps.
Remember the acronym "Oil Rig". Oxidation is loss, Reduction is gain of electrons. Calcium is losing electrons so it's an oxidation reaction.
