Which method of testing substances is a sure way to identify a chemical reaction? a. change in color
b. formation of bubbles
c. change in density
d. increase in temperature
e. solubility in water

it can only be one! ! im desperate!

Three alkali metals in group 1 are a. calcium, strontium, barium b. boron, aluminum, gallium c. sodium, potassium, rubidium d. fluorine, iodine, chlorine

Which fact represents evidence for the big bang theory?

The gulf stream is a warm water current that flows away from the equator to northern europe. witch of these does it cause. a. crashes of warm and cool water in the ocean b.colder climates near the equator c.large waves on the cost of europe d.warm climates in northern europe