Which of the following statements is true? Edward Jenner developed the first vaccine for cowpox.
Before Jenner's vaccine, there was no prevention for smallpox.
Vaccination is only necessary for children under 5 years old.
Missed vaccinations can be given during "catch-up" periods.

help PLEASE I HAVE 2 minutes

Amixture of gaseous sulfur dioxide and oxygen are added to a reaction vessel and heated to 1000 k where they react to form so3(g). if the vessel contains 0.669 atm so2(g), 0.395 atm o2(g), and 0.0851 atm so3(g) after the system has reached equilibrium, what is the equilibrium constant kp for the reaction: 2 so2(g) o2(g) ⇌ 2 so3(g)

Which of these expressions are correct variations of the combined gas law? p1v1t2 = p2v2t1 both

What must be in balance for temperatures to remain constant?