Which balanced equation represents an endothermic reaction?

(1) C (s) + O2 (g) → CO2 (g)

(2) CH4 (g) + 2O2 (g) → CO2 (g) + 2H2O (l)

(3) N2 (g) + 3H2 (g) → 2NH3 (g)

(4) N2 (g) + O2 (g) → 2NO (g)

Determine the number of atoms in 0.075 mol of Carbon (C) ? a. 4.5 x 1022 atoms b. 1.2 x 1023 atoms c. c. 6.2 x 1023 atoms d. 2.2 x 1024 atoms

What do the elements in each pair have in common? k, kr be, mg ni, tc b, ge al, pb?

If a landlord does not allow you to have pets in the building, but allows you to have a dog, is that an exception? Why or why not?

According to Bohr's model of the hydrogen atom, what determines the energy of an electron? A. the radius of its orbit B. the direction of its orbit C. the stability of its orbit

Soil erosion is a secondary environmental problem because it only degrades the land and does not affect water or air quality. True or false?

What percentage of the naphthalene molecules emitted a photon?

In an endothermic reaction, heat is absorbed from the surroundings. How does this affect entropy? A. The particles in the surroundings move slower and have decreased entropy. B.

The temperature of a sample of liquid water changes from 50°C to 30°C. Which statement best explains the change that must happen at the molecular level? A. The molecules move more quickly and their average kinetic energy increases. B.

The most important reason why solid sodium hydroxide is not used as a primary standard is

plate a and plate b are both continental plates. what is ghe most likely result if the two plates collide?