For which compound is the process of dissolving in water exothermic?

(1) NaCl (3) NH4Cl

(2) NaOH (4) NH4NO3

What is the SI unit for weight

What does the atomic number of an element represent? A) the number of orbitals B) the number of electrons C) the number of neutrons D) the number of protons

If you can walk 2.1 miles in 35 minutes, how many days will take you to con the United States (3350 mi) if you walk 8 hours a day

Doppler shifted hydrogen absorption lines are seen in the spectrum of a star. The hydrogen line at 656.28 nm is seen to be shifted to 656.08 nm. Is the star moving towards or away from us, or can we not tell?

Water was added to 175mL of a KOH solution until the volume was 250 mL and the molarity was 0.315 M. What was the molarity of the initial concentrated solution?

Which of the following statements about transition metals is true? a. They are never found uncombined in nature. b. They include familiar metals such as gold, silver, copper, and nickel. c.

Elements can be separated from one another. Question 6 options: True False

One gram of lipid yields about 9kcal of energy. that is due to the high abundance of which chemical element?

Which of the following happens during a chemical change? Check all of the boxes that apply 0 One atom or more changes into atoms of another element. New substances with different properties are formed. O Solids, liquids, or gases may form.

The energy derived from the movement of H + ions down an electrochemical gradient from the intermembrane space into the matrix is used to drive the synthesis of ATP. How many H + ions must be moved into the matrix for the synthesis of 1 ATP?