Isotopes are chemical elements with same atomic number (Z), but different mass number (different number of neutrons).
Hydrogen is an element with atomic number 1. It has three isotopes:
1) protium (₁¹H), with mass number 1 (no neutrons).
2) deuterium (₁²H), with mass number 2 (one neutrons, n° = 2 -1, n° = 1).
3) tritium (₁³H), with mass number 3 (two neutrons, n° = 3 -1, n° = 2).
Answer: There are molecules in 6.73 moles of phosphorus trichloride
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number of particles.
1 mole of contains = molecules
Thus 6.73 moles of contains = molecules
Thus there are molecules in 6.73 moles of phosphorus trichloride
Evaporation can decrease the amount of water. Dust from the surroundings can enter the water. The water can freeze if the surrounding temperature decreases sufficiently.