Answer:
Basing on explanations below;
1. Endothermic reactions have a positive enthalpy while Exothermic reactions have a negative enthalpy.
2. Endothermic reactions take place in high temperatures while Exothermic reactions take place in low temperatures.
Because as you change the mass the volume will change and as you change the volume the mass will change too, it's a constant ratio for each element. Mass and volume are not factors that affect the density. factors that affect the density are temperature and type of the material/element
A slice of pizza is an example of a Heterogeneous mixture.
Answer:
1: The speculation that continents might have 'drifted' was first put forward by Abraham Ortelius in 1596. The concept was independently and more fully developed by Alfred Wegener in 1912, but his hypothesis was rejected by many for lack of any motive mechanism. 2: The most obvious evidence for continental drift is that the continents appear to fit together like pieces of a puzzle. But scientists were skeptical , and Wegener needed additional evidence to support his hypothesis. Glaciers covered large areas that are now parts of these continents.
