Scientists have hypothesized that oxygen began to build up in the Earth's atmosphere after the development of living things with the ability to

a. breathe air.

b. form tissues.

c. photosynthesize.

d. reproduce sexually.

If the [H3O+] of a solution is 1x 10-8 mol/L the [OH-] is

What is a compound element?

Compare the hydronium ion concentration of the solution having a ph of 2.0

If a what and a what is close enough they wil form a nova

What would be the mass of a 45 cm^3 cube of Uranium?

The reaction below has an equilibrium constant kp=2.2*106 at 298 k. 2cof2 (g) ⇌co2 (g) + cf4 (g) calculate kp for the reaction below. cof2 (g) ⇌12co2 (g) + 12cf4 (g)

The electrical conductivities of the following 0.100 M solutions were measured in an apparatus that contained a light bulb as the indicator of conductivity. Rank the solutions in order of decreasing intensity (brightest to dimmest) of the light bulb.

What is the name of a list of elements arranged according to the ease with which they undergo certain chemical reactions?

Why is it harder for the earth to recover from some natural disasters now? A) Human influence may compound the damage. B) The natural disasters have gotten worse. C) This statement is not true.

Heat is most closely related to ___ energy. A. Nuclear B. Electrical C. Thermal