How many neutrons does a beryllium atom with four protons and a mass number of nine?

Which statement correctly describes potassium iodide, ki? there is a one-to-one ratio of potassium ions to iodide ions. potassium gains electrons and iodine loses electrons during the reaction. the lattice is held together by potassium anions and iodide cations.

Asample of ammonia reacts with oxygen as shown. 4nh3(g) + 5o2(g) 4no(g) + 6h2o(g) what is the limiting reactant if 4.0 g of nh3 react with 8.0 g of oxygen? o2 because it produces only 0.20 mol of no. nh3 because it produces only 0.20 mol of no. o2 because it produces two times less no than nh3. nh3 because it produces three times more no than o2.

2pos suppose an object in free fall is dropped from a building. its starting velocity is 0 m/s. ignoring the effects of air resistance, what is the speed (in m/s) of the object after falling 3 seconds? give your answer as a positive decimal without units. answer here