while completing an obstacle course a runner moves 30m north, 20 m south, then another 5m north at the end of the course, how far away from his starting point?

no statements shown

the atomic number of carbon is six, which means that a carbon atom has six protons. carbon has three naturally occurring isotopes: carbon-12, carbon-13, and carbon-14. which of these statements are true about carbon and its isotopes? select all that appl