Im not positive but i think it is When it is a gas?
Answer:
if u know the number of electrons u also know the number of protons present in the atom.
Answer:
Sample A is a mixture
Sample B is a mixture
Explanation:
For sample A, we are told that the originally yellow solid was dissolved and we obtained an orange powder at the bottom of the beaker. Subsequently, only about 30.0 g of solid was recovered out of the 50.0g of solid dissolved. This implies that the solid is not pure and must be a mixture. The other components of the mixture must have remained in solution accounting for the loss in mass of solid obtained.
For sample B, we are told that boiling started at 66.2°C and continued until 76.0°C. The implication of this is that B must be a mixture since it boils over a range of temperatures. Pure substances have a sharp boiling point.
Answer:
Start and end times; distance run.
Step-by-step explanation:
Average speed = distance/time.
Kaila should record the distance run, the time she started, and the time she ended her run.
The difference between the start and end times gives the time for the run.
If she inserts her numbers into the formula, she will get her average running speed.