J.J. Thomson's experiments with cathode ray tubes showed that all atoms contain tiny negatively charged subatomic particles or electrons. ... Rutherford's gold foil experiment showed that the atom is mostly empty space with a tiny, dense, positively-charged nucleus.
Using the mass/volume percentage method for percentages of the solution, you simply divide the grams of solute by the volume of the solution and multiply by 100 to get your percentage.
(75.0g/250mL)•100 = 30.0% solute
Answer : The new pressure if the volume changes to 560.0 mL is, 280 mmHg
Explanation :
According to the Boyle's, law, the pressure of the gas is inversely proportional to the volume of gas at constant temperature and moles of gas.

or,

where,
= initial pressure = 560.00 mmHg
= final pressure = ?
= initial volume = 280 mL
= final volume = 560.0 mL
Now put all the given values in the above formula, we get:


Therefore, the new pressure if the volume changes to 560.0 mL is, 280 mmHg
Answer:
repetition
Explanation:
Taking an average of 16 height measurements is an example of repetition. Repetition involves making and taking repeated measurements in an experiment.
The goal is to achieve a highly accurate and precise data from the experiment.
- Replication involves duplicating another experiment and testing to see how valid they are.
- Since Veronica's experiment is a brand new one, it's hypothesis has not been tested or replicated in any way.
- Therefore, it is not a replication.
- But she is repeating the experiment to obtain different values.