Answer:
1. an eclipse of the Sun
2. state (phase) of matter
3. 5.0 g/cm3
Explanation:
1. Eclipse of the sun occurs when the planetary bodies align in such a way that causes the moon to block sunlight from reaching the Earth. The eclipse of the Sun will be the most predictable occurrence because it follows a pattern of occurrence. Eclipse of the sun occurs after a specific period of time, hence, based on this, scientists can predict that when it will occur next using its previous pattern of occurrence.
2. Considering the following groups: Group A: water, aluminum, water vapor
Group B: gasoline, ice, air
Group C: alcohol, iron, oxygen
One would realize that each constituent of each group exists in a particular state of matter. For example, in group B, gasoline is a liquid, ice is a solid while air is a gaseous mixture. Same applies for group A and C where water and alcohol are liquids, iron and aluminum are solids, while water vapor and oxygen are gases.
This shows that the STATE (PHASE) OF MATTER was the basis of classification.
3.
