If the radioactive isotope of a particular element has a half-life of 15,000 years, how old is a sample that has 12.5% of the parent isotope remaining

How many moles are equivalent to 55.5g of nano3

Use the periodic table to complete this equation that represents nuclear fission processesun - ba c 3 n

Inside a flashbulb, oxygen surrounds a thin coil of magnesium. when the flashbulb is set off, a chemical reaction takes place in which magnesium combines with oxygen to form magnesium oxide. which of the chemical equations matches the reaction above? a. mg + o2 mgo2 + energy b. 2mg + o mg2o + energy c. 2mg + o2 2mgo + energy d. mg + o mgo + energy