Sr2 has 36 electrons in total.
Answer:
Physical properties: how soft a blanket it, how hard bread is, what color leaves are, what bleach smells like.
Chemical change: burning wood, rotting food, digestion, rusting of a nail.
Physical change: mixing salt and sugar, tearing a piece of paper, melting ice, chopping wood.
Explanation:
Physical properties are properties that are measurable.
Chemical change is when substances combine (fire and wood make burning wood) to make another substance. They aren't reversible. If you were to melt ice, you could refreeze it, you can't unburn wood.
Physical change is something that alters the form of the substance but not the chemical composition.
Hope this helps!
Answer:
Removing the dirty water and replacing with fresh water. also the fish containing in the aquarium change the system of aquarium.
