Areaction showing heat as a product is an exothermic reaction.

true

false

Which statement describes the appearance of a temperature-vs.-time graph? a horizontal line shows that the temperature increases at a constant rate over time. a vertical line shows that the temperature decreases at a constant rate over time. horizontal lines where the temperature is constant during phase changes connect upward-sloping lines where the temperature increases. horizontal lines where the temperature increases are connected by upward-sloping lines where the temperature is constant for each phase.

What are scientists who study fossils called? ( a ) astronomers. ( b ) biologists. ( c ) geologists. ( d ) paleontologists.

Which element has the lowest electronegativity? calcium(ca) gallium(ga) selenium(se) bromine(br)