if you start with 48 g of a radioactive substance and have 0.75 g left how many half lives have elapsed

From the following enthalpy of reaction data and data in Appendix C, calculate ΔH∘f for CaC2 (s) : CaC2 (s) + 2H2O (l) →Ca (OH) 2 (s) + C2H2 (g) ΔH∘=-127.2kJ

Which of these four contain an ionic bond, H2O, CO, P2O5, or AlCl3? i answered earlier and I was wrong.

What is the input of a flashlight

What does the atomic number tell us?

What causes the matter and energy for plate motion?

Nonmetal oxides can react with water to form acids. For example, carbon dioxide reacts with water to form carbonic acid: CO2 H2O H2CO3. (1) Write an equation to show how diiodine pentaoxide reacts with water to form an acid. Do not include states.

If atmospheric pressure suddenly changes from 1.00 atm to 0.892 atm at 298 k, how much oxygen will be released from 4.40 l of water in an unsealed container?

Determine the molecular formula for the unknown if the molecular mass is 60.0 amu and the empirical formula is ch2o.

Draw the organic product of the following nucleophilic reaction

How does the energy of the activated complex compare with the energies of reactants and products? select one: a. it is lower than the energy of both reactants and products. b.