Explain how to determine the number of valence electrons an element has.

Pentaborane b5h9 (s) burns vigorously in o2 to give b2o3 (s) and h2o (l). what is δh° for the combustion of 1 mol of b5h9 (s) ? substance δh°f (kj/mol) b2o3 (s) - 1273.5 b5h9 (s) + 73.2 h2o (l) - 285.8

The volume of a gas increases from 2.0L to 2.25L. If the original pressure was 1.1 atm calculate the new form.

How is the information about cats found in myths and fairy tales and legends different from information gathered through science

The complete combustion of octane, C8H18, the main component of gasoline, proceeds as follows: 2C8H18 (l) + 25 O2 (g) - - > 16 CO2 (g) + 18 H2O (g) a. How many moles of 02 are needed to burn 1.50 mol of C8H18? b.

Name four metals and non-metals, and state one major use of each

The flame from my candle gives off black smoke heat and light what type of changes do these indicate

Which one of the following processes results in a decrease in the number of neutrons? corrosion electron capture gamma emission positron emission alpha emission

Calculate the root mean square velocity of F2, Cl2, and Br2 at 304 K.

The total pressure inside a 1.62 cylinder kept at 35°C is 1.15 atm. If the volume of the cylinder drops to 0.74 L and the temperature remains the same, what is the new pressure inside the cylinder?

What is difference between tempering and aging?