I think the word you're looking for is "hypothesis".
For example, a hypothesis could be "dogs drink more often when owners are present".
And then this can be proven (or dis-proven) by an observation (or in this case rather: measurement).
No, a sandwich uses bread. Hotdog uses buns.... unless you are cheap and use bread. Still not a sandwich though.
Cereal is not soup. If it were, it would just be called breakfast soup... but it’s not, it’s called cereal... so, no.
A political map. This is because it shows population of people and their movements into certain regions
The most important producer in both freshwater and marine ecosystems is phytoplankton.
On February 21, 1972<span>, President Richard M. Nixon arrived in China for an official trip. He was the first U.S. president to visit the People's Republic of China since it was established in </span>1949<span>. This was an important event because the U.S. was seeking to improve relations with a Communist country during the Cold War.</span>
