Which of the following groups contains reactive elements that need to gain only one electron to have a full outer energy level? alkali metals alkaline earth metals halogens noble gases

Often on a topographic map, every fifth contour line is darkened. what is this line called? a. key b. slope c. benchmark d. index contour

Joan writes four numbers on the board in standard form, and then she writes their scientific notation

Consider the following reaction at equilibrium. 2co2 (g) 2co (g) + o2 (g) h° = -514 kj le châtelier's principle predicts that the equilibrium partial pressure of co (g) can be maximized by carrying out the reaction a. at high temperature and high pressure b. at high temperature and low pressure c. at low temperature and low pressure d. at low temperature and high pressure e. in the presence of solid carbon