Answer:
A. Yes, the substance must be water.
Explanation:
The density of a substance is unique to it. Density is defined the as the amount of substance contained per volume.
One of the ways of identifying a substance is to determine its density. Every matter is known to have their own specific densities. This makes them different from other substances. The density of gold is unique to it and it differs from that of silver.
In fact, water has density of 1.00gcm⁻³. Experimental errors and some little factors must have altered our expected figure. This a case of precision and accuracy in the experiment.
Answer:
0,0,0,0
Explanation:
The formal charge formula:

So:
Hydrogen: 1 elec. of valence and shares two electrons with the O

Oxygen: 6 elec. of valence, 2 lone pairs and shares two electrons with the H and two with the F

Fluorine: 7 elec. of valence, 6 lone pairs and shares two electrons with the O

Oxygen: 6 elec. of valence, 3 lone pairs

Note: the dative bond between F and the second O doesn't count as shared electrons.
Answer:
temperature of the water
Explanation:
Density is defied as mass divided by the volume. To investigate how the density of water change with temperature, Bob have the change the temperature and read the volume and mass of the investigated sample.
Even if there is a different salt content between booted water or tap water and have an influence on the density (compared with pure water), this difference is not so big so the change in density with temperature can be determined. Considering that the experiment do not require extreme accuracy, any type of water may be used (bottled water of tap water).
Answer:
accelerating
Explanation:
technically, there is no such thing as deceleration, just negative acceleration.
Strong covalent bonds require significant energy to be broken?