Element that has two isotopes has an average atomic mass of 199.7. if 75.56% of the atoms of the element have an atomic mass of 197.4, what is the atomic mass of the other isotope?

The phosphorous anion (P-) has how many total electrons and how many valence electrons? a. 14; 6 b. 16; 5 c. 14; 4 d. 16; 4 e. 15; 5 f. 14; 5 g. 15; 4 h. 15; 6 9. 16; 6

A dozen is 12 of anything. One mole is 6.022 * 10^x of anything. What is the exponent (shown by the variable "x") for the value of one mole?

Are all single replacement reactions considered redox reactions?

Write the balanced neutralization reaction that occurs between H 2 SO 4 and KOH in aqueous solution. Phases are optional.

Using two different instruments I measured the length of my foot to be 27 centimeters and 27.00 centimeters. Explain the difference between these two measurements.

How do carbohydrates relate to organic chemistry

Periodic table, chemistry questions who discovered lanthanides. how did they discover it, when did they discover it.

A flask containing 155cm^3 of hydrogen was collected under a pressure of 22.5kPa. What pressure would have been required in order for the volume of the gas to have been 90.0 cm^3 at constant temperature?

Which change is most likely to occur when a molecule of H2 and a molecule of I2 collide with proper orientation and sufficient energy? 1. a chemical change, because a compound is formed 2. a chemical change, because an element is formed 3.

Which substance is a diatomic molecule? a. he b. o2 c. co2 d. h2o?