Write an electron configuration for an atom of aluminum-27 in an excited state

20. The mass of one mole of lead (Pb) atoms is 207.2 g. Use a proportion to calculate the n lead atoms in a 15.00 g sample of lead. 2. Y i n the mathematical relationship between atomic mass units (amu) and grams (g) ?

Which example is a renewable energy source? a) sunlight b) coal c) anthracite d) natural gas

Use each equation to predict whether the relative entropy change is S (products) > S (reactants) or S (products) 0 or ΔS < 0 for the chemical reaction represented. Justify your answer in each case. a. 2NH3 (g) →N2 (g) + 3H2 (g) b.

To find the volume of a few small marbles a student will need which of the following scientific tools?

Calculate the ph of a 3.78*10-3 m solution of naf, given that the ka of hf = 6.80 x 10-4 at 25°c.

8. which change in state is associated with the heat of vaporization, 1. solid to liquid 2. liquid to vapor 3. solid to vapor 4. liquid to solid

A mixture of calcium carbonate, CaCO3, and barium carbonate, BaCO3, weighing 5.40 g reacts fully with hydrochloric acid, HCl (aq), to generate 1.39 L CO2 (g), mea sured at 50°C and 0.904 atm pressure.

Which of the following is the major advantage of using geothermal energy instead of using coal energy? Choice: You will get a brainliest! If your correct! A. More abundant than coal B. Easier to access than coal C. Releases less carbon dioxide D.

Why can equilibrium not be reached in reversible enzymatic rxn?

The nh2cl model consists of balls and sticks. the electrons in the molecule are paired, and each stick represents a valence electron pair. how many sticks do you need?