Calculate the value of Delta H for the reaction CaCO3 --> CO2 + CaO from the following enthalpy changes: Ca + C + 3/2 O2 --> CaCO3 ΔH = -1206.9 kJ
Ca + ½ O2 --> CaO ΔH = -635.1 kJ
C + O2 -->CO2 ΔH= - 393.5 kJ

Sally is making a model of a magnesium atom with an atomic mass number of 24 for her chemistry class. she has foam balls for the protons, neutrons, and electrons. she has added 6 neutrons to her model so far. how many more neutrons does she need to add to complete her neutral atom of magnesium?

How many moles of oxygen gas are produced from the decomposition of six moles of potassium chlorate

Which three statements represent the benefits of performing experiments using computer simulations?