The simplest formula for a compound made from element x this 21 nitrogen by mass is

Which statement describes the appearance of a temperature-vs.-time graph? a horizontal line shows that the temperature increases at a constant rate over time. a vertical line shows that the temperature decreases at a constant rate over time. horizontal lines where the temperature is constant during phase changes connect upward-sloping lines where the temperature increases. horizontal lines where the temperature increases are connected by upward-sloping lines where the temperature is constant for each phase.

An observation that requires measurement is called quantitative observable or qualitative

The reactions shown here can be combined to make the overall reaction c(s) + h2o(g) ⇌ co(g) + h2(g) by reversing some and/or dividing all the coefficients by a number. a. c(s) + o2(g) → co2(g) k=1.363×10^69 b. 2 h2(g) + o2(g) → 2 h2o(g) k=1.389×10^80 c. 2co(g) + o2 (g) → 2 co2(g) k=1.477×10^90