What are all the forces and changes that the electron undergoes as it forms an intramolecular bond with oxygen to form a water molecule

Marcel just purchased 1.69 grams of iron fillings in order to make living putty for his 6 year old niece. how many moles of iron are made in his sample?

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

If e is the symbol for an element, which two of the following symbols represent isotopes of the same element? 1. e2. e3. ea.1 and 2c.1 and 4b.3 and 4d.2 and 3