Who what when where how.

Imagine that you push on a large rock. at what point does your effort change the rock’s mechanical energy?

How many protons, electrons, and neutrons are in each of the following isotopes? a. zirconium-90 b. palladium-108 c. bromine-81 d. antimony-123

Which answer tells the reason the earth’s climate is getting warmer? too many animals are becoming extinct. large glaciers are melting in antarctica. the earth is moving closer to the sun. driving cars gives off gases that trap heat in the atmosphere.