Which of the following represents an endothermic reaction? Select one:

a. S(s) +O2(g) → SO2(g) ΔH = -297kJ

b. 2NO2(g) → N2(g) + 2O2(g) + 33.8kJ

c. N2(g) + 2O2(g) + 90.4kJ → 2NO2

d. N2H4(g) + O2(g) → N2(g) +2H20(g) + 627.6 kJ

Which statement accurately describes the relationship between air pressure, air density, or altitude? as altitude increases, pressure increases.as altitude increases, air density increases.air pressure and density are lowest at sea level.denser air exerts more pressure than less dense air.

What is the mass of 8 moles of sodium atoms

Acandle’s wick is the fabric string that holds the flame, and it burns down at a constant slow pace when the candle is lit. the wick is usually surrounded by wax. which is the most important property of covalent compounds that makes them useful for making candle wax? a low boiling point a low melting point a high boiling point a high melting point