Answer: Event 1 is an example of a physical change and Event 2 is an example of a chemical change.
Explanation: Physical change is one in which there is no change in chemical composition of the substance. There is only a change in phase change.
Chemical change is a change in which there is a change in chemical composition and there might or might not be a phase change.
On Boiling, the water molecules remain bonded in the same form and only covert from liquid to gaseous form, thus is a physical change.
On Rusting of iron nail, the iron changes to iron oxide by combining with oxygen, there is a rearrangement of atoms and thus is a chemical change.

Answer:
The frog has 4 toes on each foot in the front, and 5 toes on each foot in the back.
Explanation:
Answer:
The correct answer is option A.
Explanation:
Volumetric flask : A glass ware with round lower body with flat bottom and with thin cylindrical neck along with mark which indicates the specific volume filled to that mark.It is used in preparation of standard solution of compound with desired concentration with fixed volume.
Erlenmeyer flask
: is a flask with conical shape with flat bottom used in titration experiments to carry out reaction with fixed volume of solution.
Test tube
: Small cylindrical tube with rounded bottom used to observe reaction in between reactant taken in small amount.
Graduated beaker
: Laboratory glassware used measure larger volumes of solution or to mix or stir solutions and liquids.
Graduated cylinder : Laboratory thin cylindrical glassware with accurate marking of volume used to measure an accurate volume of solutions or liquids required in an experiment.
<em><u>Volumetric flask</u></em> is the best piece of laboratory glassware for preparing 500.0 mL of an aqueous solution of a solid
I would say B because c and d would decrease competition and a would do the same, or just kill the ecosystem.
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The shape of the molecule will determine the direction of each of the individual bond dipoles, and thus, will always play a role in determining the polarity of the molecule as a whole.