Why are some isotopes radioactive?

Why did one liter of nitrogen prepared by lord rayleigh appear to have a greater mass than the other liter prepared by a different method?

What role does the wire play in voltaic cell

In one or two sentences explain why fossil fuel combustion is a one-way path while the combustion of modern plant materials is a cycle.

Based on your answer to part c, how many bonding electrons and nonbonding electrons are there in the lewis structure of hcn?

Estimate the volume, v, of one sodium atom (na) using its metallic radius of 186 pm. express your answer with the appropriate units.

Identify the spectator ions in the following complete ionic equation. 2k (aq) s2 - (aq) pb2 (aq) 2no-3 (aq) →pbs (s) 2k (aq) 2no-3 (aq) express your answers as ions separated by a comma.

4. A bird left its post and flew in a triangular path. It flew 21 yards south, 72 yards east and 75 yards diagonally to end back at the post. Is it a right triangle?

Condension occurs in the inside of your windows in Winters, why?

How can you use Hess's law to determine a reaction's enthalpy?

7. How much energy in KJ is released when 15.0 g of steam at 100.0 degrees Celsius is condensed and then frozen to ice at 0.0 degrees Celsius?