Answer:
platinum-189 symbol is PT
The number of joules released when 0.64g of steam are cooled from 125 c to 105 c is -26.112 joules
calculation
by use of Q=MCΔ T formula calculate the joules released where
Q( heat) =?
M (mass) = 0.64 g
C (specific heat capacity = 2.04 j/g/c
ΔT(change in temperature) = 105-125 =-20c
Q is therefore = 0.64 g x2.04 j/g/c x -20 c = -26.112 joules
it is okay to have negative value since the reaction is exothermic that is heat is released
Answer:
Explanation:
Given that:
The mass of sodium crystal = 4.14 g
As a result, the number of atoms in the sodium crystal is:

= 1.084 × 10²³ atoms
In the valence orbital of the sodium atom, there is just one electron.
As a result, the number of molecular orbitals produced by these atoms is= 1.084 × 10²³ molecular orbital
Because valence bands are created from occupied molecular orbitals, the number of valence bands created from the aforementioned molecular orbitals is:

= 5.420 × 10²² orbitals.
The new volume of the bag : 747.43 ml
<h3>Further explanation</h3>
Charles's Law
When the gas pressure is kept constant, the gas volume is proportional to the temperature

V₁=250 ml
T₁=19+273=292 K
T₂=600+273=873 K
