Answer:
The safety button doesn't click before the jar has been opened because it shows a sign of freshness. Once you have opened it there is no way to make it click again.
If bacteria gets stored in the jar they will produce gas. If the button does not pop or click after opened that is a sign that it may not be so safe to eat. Clicking shows that there is still vacuum to the jar.
Explanation:
Answer:
The change in POP can not be reversed hence it is a chemical change.
Explanation:
Plaster of Paris (POP) is used to immobilize a fractured bone. The POP sets when water is added to it, it hardens irreversibly. Once it hardens, its shape can not be changed by any physical means. This means that the hardening of POP is a chemical change.
The chemical name of plaster of Paris is calcium sulfate hemihydrate. The setting of POP is an example of a chemical reaction.
Answer:
B
Explanation:
because net force changes
Different explanations that lead to the same result
-You need to substract the number of protons from the mass number.
-Mass number - atomic number= number of protons
-Following this equation:
CARBON
atomic number= 6
mass number= 12
mass number= protons + neutrons
12= 6 + x
x= 12-6
x= 6
In collecting the precipitate, it is inappropriate to heat <span>the reacted mixture and evaporate off the water because it is possible that the mixture contains other substances that precipitates as well when the mixture is being heated so you will not be able to collect what you want.</span>
