Rust on a nail is a chemical change.
Ice melting IS a physical change. Ice is made of water, when you melt ice its still water. Just in a different physical state.
I believe your answer will be 40
the mass of oxy gas would be 4.03 did i calculate that right?
The SI base units for length is meter (m) and for time is seconds (s).
The given ratio is 
Converting mm/s to m/s as:
Since, 1 mm/s = 0.001 m/s
So, 
Since, zeroes to the left side of the non-zero number are not significant hence, the evaluation of to three significant figures and answer in SI units is 
.
Answer:
A silicone atom shares an electron pair with each oxygen atom
Explanation:
Because the silicone dioxide molecule has one silicone atom:two oxygen atoms....
Hence...since silicone has four electrons in the outter shell..which are used for bonding...each oxygen atom shares two electrons(an electron pair) with the silicone atom...so as to fill the outter shell of the oxygen atom
