Why does the mass number for an element differ from the average atomic mass for the element?

What is the molarity of a saline solution that contains 0.900 g NaCl (58.44 g/mol) dissolved in 100.0 mL of solution?

True or False. Wind blows due to the differential heating of earth's surface.

Bonds between carbon and oxygen are more polar than bonds between sulfur and oxygen. nevertheless, sulfur dioxide (so2) exhibits a dipole moment while carbon dioxide (co2) does not. explain. (problem 1.31)

1. How does the period (row) in which an element is located relate to the number of shells that contain electrons? 2. How does the group (column) in which an element is located relate to the number of valence electrons in its outer shell? 3.

Is it true oxygen is an excellent solvent that is capable of dissolving just about anything?

A sample of hydrogen gas is mixed with water vapor. The mixture has a total pressure of 755 torr and the water vapor has a partial pressure of 24 torr. What amount (in moles) of hydrogen gas is contained in 1.55 L of this mixture at 298 K?

Both equation I and II are balanced, but equation II is the correct way to write the balanced equation. Why do you think this is? (Hint: Think fractions.) I) 2 SnO2 + 4 H2 → 2 Sn + 4 H2O II) SnO2 + 2 H2 → Sn + 2 H2O

If some of the salt remains adhered to the weighing paper (and therefore is not transferred to the calorimeter), will the enthalpy of solution for the salt be reported too high or too low?

In one process, 5.95 kg of caf2 is treated with an excess of h2so4 and yields 2.45 kg of hf. calculate the percent yield of hf.

What are 3 ways to increase the solubility of a solid substance in a solid?