Moles = mass / molar mass
molar mass of O2 is 32
therefore moles = 72/32
= 2.25 moles
Answer:
C
Explanation:
The early ideas of the atom states that the indivisible object is hollow or is a solid object with nothing inside. The later discoveries or works of the scientists states that inside the atoms are the subatomic particles which are the electrons, protons, and neutrons.
C. Condensing.
Why: Because, Condensing means to make something denser or more concentrated.
Hope this helps! ;)
Answer:
Ca, Zn, Ni, Al, Fe
Explanation:
The activity series is an arrangement of metals in order of decreasing reactivity.
Metals that are high up in the activity series are very reactive. They displace metals that are lower in the activity series from an aqueous solution of their salts.
The metals; Ca, Zn, Ni, Al, Fe are all above Pb in the activity series hence they will cause Pb2+ ions to come out of solution as solid Pb.
