Briefly explain at least two lines of evidence to explain how we know for certain that combustion of fossil fuels is responsible for the increase in carbon dioxide, rather than non- human sources such as volcanoes or plants.

Put these processes of the water cycle in the correct order, starting at the point where the water is in the lake: 1. water evaporates into the atmosphere 2. rain, snow, or other precipitation falls 3. water collects into larger bodies of water 4. water vapor condenses into liquid water

Which statements are true concerning mineral formation? check all that apply. the slower the cooling, the larger the crystals. the faster the cooling, the smaller the crystals. crystals formed from magma are smaller than crystals formed from lava. minerals can only form in solutions when the solution is heated deep underground. when a solution cools, elements and compounds leave the solution and crystallize as minerals. minerals formed from hot water solutions can form narrow channels in the surrounding rock.

The semi-conductors on the periodic table are classified as