The burning of fossil fuels for energy in the modern era of life on earth is resulting in a significant increase in total co2 concentration in earth's atmosphere. however, the ratio of 14c to 12c is decreasing. why is this?

Three cards with holes are arranged in a straight line. a light is shined through the first card’s hole and travels through all three cards. what does this tell you about light rays? a) that light is reflected b) that light is refractive c) that light travels in a straight line d) that light does not travel in a straight line

Which process does not require the presence of a physical substance in order to transfer heat? air in the atmosphere is heated by the ground. this warm air then rises, and cooler air falls. this is an example of what type of process? how is conduction different from radiation?

How do you identify the anode on a power source such as a battery? how do you identify the cathode? how are terms anion and cation?