Oxygen and fluorine are gaseous elements that are adjacent in the Periodic Table. When both are under the same temperature and pressure conditions, oxygen diffuses ......1...... more slowly than fluorine because its ......2...... is lower than fluorine's. Which words correctly fill gaps 1 and 2?
- A1 faster; 2 molecular mass
- B1 faster; 2 reactivity
- C1 slower; 2 molecular mass
- D1 slower; 2 reactivity