The two most abundant elements in the universe are:

a. Hydrogen and Oxygen

c. Hydrogen and Helium

b. Oxygen and Nitrogen

d. Carbon and Oxygen

For the reaction NH4NO3 (s) → N2O (g) + 2H2O (l), you decompose 60 g of NH4NO3 and get 11 g of N2O. What is the percent yield? Question 8 options: 25% 33% 90% 65%

What can be used to determine the relative age of two rocks? A. vertical position B. the presence of unconformities C. radioactive dating of each layer D. The relative age cannot be determined.

Why is 18-karat gold considered a mixture rather than a pure substance? A) It has a variable composition. B) Its color is different than pure gold. C) The gold atoms are not arranged in a repeating pattern.

4. What two sets of units can be used to describe density? Why are they interchangeable? a. b. c.

What amount (moles) is represented by each of these samples? (a) 22.5 mg lye, NaOH mol (b) 2.57x1021 molecules of chalk, CaCO3 mol (c) 1.46 g of sucrose, C12H22011 mol

Describe the change in energy that occurs as bonds are broken and formed

What element is in column 7A period 4? Select one: 0 a. Manganesse b. None of these are in that location c. lodine d. Bh - Element #107 e. Bromine

An element's atomic number is 60. How many electrons would an atom of this element have?

El vinagre es una suspensión?

How many liters of hydrogen gas are needed to react with cs2 to produce 2.50 l of ch4 at stp? 4h2 (g) + cs2 (l) → ch4 (g) + 2h2s (g) ?