You started with 64 g of a radioactive substance. If you have 4.0 g of that substance left, then how many half-lives have elapsed?

a. 2

b. 3

c. 4

d. 5

Which product of the ultraviolet decomposition of cfcs acts as the catalyst for ozone decomposition?

Consider the reaction of CaCN2 and water to produce CaCO3 and NH3 according to the reaction CaCN2 + 3H2O → CaCO3 + 2 NH3. How much CaCO3 is produced upon reaction of 45 g CaCN2 and 45 g of H2O? 1. 750 g 2. 250 g 3. 56 g 4. 19 g 5. 83 g 6. 28 g 7.

Explain the connection between energy quanta and energy levels.

How many liters of oxygen are released from the decomposition of 36.5 grams of hydrogen peroxide at STP?

When the volume of a gas is changed from 3.6 L to 15.5 L, the temperature will change from oC to 87°C

What is the mass (in grams) of 9.09x10^24 molecules of methanol (CH3OH) ? AND How many moles of N are in 0.183g of N2O?

What are the basic building blocks of matter? A) molecules B) atoms C) electrons D) compounds

How does an atom with too few neutrons relative to protons undergo radioactive decay? * by converting proton to a neutron by converting a neutron to a proton by emitting an alpha particle

What is the chemical formula for the compound formed between sodium and iodine?

8. Write a balanced chemical equation showing how you could prepare each of the following salts from an acid-base reaction: KNO3, NaBr, and Cas.