... liquid water are two different forms of the same chemical substance, water. A chemical substance is a form of matter that has constant chemical ...
Answer:
1.Hydrogenation of Alkenes and akynes.
2.Reaction of alkylhalides.
3. Halogenation.
Answer:
a pencil being sharpened
freezing water
boiling water
Explanation:
a physical change doesn't change the chemical structure of an object. That is why the other 2 are wrong
Answer:
A. Water
Explanation:
H2O means that there are two hydrogen and one oxygen in every water molecule.
Answer:
v = 658.82 km/h
Explanation:
The distance between New York and London is 
Time taken from New York to London is 8.5 hours
We need to find the average speed of the plane.
Total distance covered divided by the total time taken is equal to the average speed of an object. So,

So, the average speed of the plane is 658.82 km/h.