Which of these describe the composition of earths atmosphere?
a) mixture
b) substance
c) compound

Which configuration would produce an electric current? a) rotate a coil of copper wire between two magnets. b) connect a wire between a copper and zinc strip sitting in a beaker of water. c) connect a wire to the (+) positive end of a battery and the other end to a light bulb. d) connect a wire to the negative end of a battery and the other end to a light bulb.

Ineed the answer to question 1 , i’m desperate

If a simple machine reduces the strength of a force, what must be increased?