How many atoms would be left after 21.39 s if you started with 7000 atoms of nitrogen-13 and the half-life is 7.13s

What is driving behind plate tectonics (plate movment)? a) gravity only b) inertia c) convection and gravity d) the sun theres no option for science so i picked chemistry. plz

What is the most stable monatomic ion formed from nitrogen

When hydrochloric acid reacts with potassium hydroxide solution, the following reaction occurs. hcl (aq) + koh (aq) h2o (l) + kcl (aq) the reaction gives off heat energy, so it is an reaction.