Which equation obeys the law of conservation of mass? H2(g) O2(g) → H2O(g) H2(g) O2(g) → H2O(g) 4He(g) 2H2(g) O2(g) → 2H2O(g) H2(g) → H2O(g) H2(g) O2(g) → 2H2O(g).

Why should the scientific method be used to answer a question? a. it provides a way to test an idea without any bias. b. it provides a way to test a hypothesis. c. it provides a way to ensure all hypotheses are proven correct. d. it provides a way to quickly turn a hypothesis into a scientific theory.

What is the formula that this ionic compounds could form sr2+p3-o2-

How many moles of air are there in a human lung with a volume of 2.4 l at stp? explain your answer