True because it seems that is like a pattern it's always 6
Physical changes happen when you do/mix something that can be reversed. Best example is ripping a paper, you can just tape it back together so it is just an observable thing that changes, which is a physical change. Chemical changes happen when you mix things and they make a new substance and can’t be reversed. The best example of this is the Statue of Liberty, which changed in color due to the chemical change between the oxygen and copper, which created a new substance (rust) which made it green instead of copper.
Sorry for the long answer but hope this helps!
The total pressure is 6.7 atm. The mole fractions of O₂ and Ar are 0.42 and 0.037.
<em>p</em>(Tot) = <em>p</em>(N₂) + <em>p</em>(O₂) + <em>p</em>(Ar) + <em>p</em>(He) = 3.5 atm + 2.8 atm + 0.25 atm + 0.15 atm = 6.7 atm
χ(O₂) = p(O₂)/p(Tot) = 2.8 atm/6.7 atm = 0.42
χ(Ar) = p(Ar)/p(Tot) = 0.25 atm/6.7 atm = 0.037
The atomic number of a neutral atom is equal to the number of protons and the number of electrons of the atom. The atomic weight meanwhile is equal to the sum of the number of protons and number of neutrons. In this case, the atomic number of the atom is 3 and the atomic mass is 7. Hence the element is Lithium, a metal
