Answer:
Pressure of the trapped gas and the pressure on the outside on the piston are the same.
Explanation:
When the piston is at rest, then it exist a mechanical equilibrium, that is to say, that pressure of the trapped gas is equal to the pressure on the outside of the piston.
Answer:
- <em>The mystery substance is</em> <u>C. Bromine (Br) </u>
Explanation:
<em>Argon (Ar) </em>is a noble gas. Whose freezing point is -189 °C (very low), thus it cannot be the frozen substance. Also, it is not reactive, thus is would have not reacted with iron. Hence, argon is not the mystery substance.
<em>Scandium (Sc) </em>is a metal from group 3 of the periodic table, thus is will not react with iron. Thus, scandium is not the mystery substance.
Both <em>bromine</em> and <em>iodine</em> are halogens (group 17 of the periodic table).
The freezing point of bromine is −7.2 °C, and the freezing point of iodine is 113.7 °C. Thus, both could be solids (frozen) in the lab.
The reactivity of the halogens decrease from top to bottom inside the group. Bromine is above iodine. Then bromine is more reactive than iodine.
Bromine is reactive enough to react with iron. Iodine is not reactive enough to react with iron.
You can find in the internet that bromine vapour over hot iron reacts producing iron(III) bromide. Also, that bromine vapors are red-brown.
Therefore, <em>the mystery substance is bromine (Br).</em>
Thomson concluded that electrons must be parts of the atoms of all elements. Millikan determined the charge and mass of the electron. What experimental evidence led Rutherford to conclude that an atom is mostly empty space? The majority of the alpha particles passed straight through the gold foil.
M = n x Mr
Mr of H20 - 18.006
M = 1.15mol x 18.006g/mol
= 20.7069g
= 20.7g (3sfg)
