In past scientist used stars and planets to determine time?

The acid-dissociation constant, Ka, for benzoic acid is 6.5 * 10-5. Calculate the base-dissociation constant, Kb, for the conjugate base of benzoic acid. A. 9.3 * 105 B. 2.5 * 10-6 C. 6.5 * 109 D. 1.5 * 10-10

How many milliliters of a 2.0 molar sodium chloride solution would be needed to prepare 250 mL of 0.15 molar sodium chloride solution?

How might Rebecca Flowers have felt when she found new evidence about the Grand Canyon. Cite an example from the text to support your answer.

Use Avogadro's number to find the number of oxalic acid molecules in 0.189 mol of H2C2O4.

Which type of chemical reaction occurs in C6H12 + 9O2 = 6CO2 + 6H2O? A) synthesis B) combustion C) single replacement D) double replacement

What element is represented by the following electron configuration: 1s22s22p63s23p64s23d4 Question 2 options: Cr Ca Ge Ar

He substance, cocl2, is useful as a humidity indicator because it changes from pale blue to pink as it gains water from moist air. What is its name?

The weighted average atomic mass of an element depends upon the a. relative abundance of protons in the element b. mass and relative abundance of each isotope of that element c. mass and relative abundance of each neutron of that element d.

What part of an atom do we change for isotopes

The Safe Drinking Water Act (SDWA) sets a limit for mercury-a toxin to the central nervous system-at 0.002 mg/L. Water suppliers must periodically test their water to ensure that mercury levels do not exceed 0.002 mg/L.